"They just treated me like a joke," she said. "They treated me with no respect and no seriousness ... they were just fake, they didn't care at all."

'I'm just really angry'

After reading her file, the girl thinks police were suspicious of her motives for reporting from the start.

Comments in her case history show detectives noted she didn't come forward until after one of the men bragged to friends about having a "threesome", and questioned why she hadn't told her parents "the whole truth of what happened".

One detective apparently even told the girl's father his daughter was "no angel", after he accused one of the men of being a rapist on social media.

The father was told by police to delete the comment, or possibly face charges himself.

The teenager now plans to lay a complaint with the Independent Police Conduct Authority (IPCA) about the way her report was handled.

She wants to know why detectives failed to interview the alleged suspects for five months after the incident; and for police to be held accountable for the way they treated her during the process, which she says only worsened the trauma of the incident itself.

"When I first went to the police I was so happy, I thought it was going to be really good," she said.

"But now I'm really sad, and hopeless and angry. I'm just really angry. It's changed my outlook on life. I just see rape culture everywhere. I always think about the bigger picture, how many other girls it would have happened to."

She said her experience of laying a complaint was so bad that her friend, who was also allegedly assaulted by one of the men, refused to talk formally to police.

"I was put off by what happened to her," the friend told the Herald. She said she spoke to an officer during the investigation but decided against making a statement.

"I'm definitely worried he might do it to other people. If I made a formal complaint that might stop him but ... I don't think the cops would do anything."

Police say their handling of the case was thorough and robust, and their decision not to proceed with prosecution - on the basis of a lack of evidence - was the correct one.

For any criminal case to go to court, there must be sufficient evidence to give reasonable prospect of conviction, and after that, it must also meet a public interest test.

Acting Southern District Commander Inspector Joel Lamb said the case had been reviewed by senior detectives not involved in the original investigation.

The texts show the girl pleading for help throughout the incident.

He said police took sexual assault very seriously and it was "entirely incorrect" to say the investigation was not given priority.

"Police understand and acknowledge that the decision not to proceed with a prosecution in this matter has been upsetting for the complainant and her parents," he said.

However he would not comment further out of consideration for the victim's privacy.

'I needed an excuse to get out'

The alleged assault happened after a birthday party in early December 2017. The complainant and the suspects belonged to the same social circle, and socialised together frequently.

After the party, the complainant and the two men went back to a flat. One man, who lived there, said he went to bed, and the girl and the second man came in afterwards.

The complainant said she had been charging her phone in the first man's room, and felt sleepy so got into the bed with one of the men. At some point, the second man came in and both began touching her.

She said she didn't reciprocate, or indicate she was interested in any way, although it was confusing because it felt good.

While she didn't say "no" outright - because she was scared and shocked - she repeatedly tried to turn away or get out of the bed, she said. From her perspective, it was clear she didn't want to be there there.

She sat up a couple of times but one of them "moved her back down". She also moved her face away when one of the men tried to kiss her, but he pushed her face back towards him.

"[I] was texting the whole time, I needed an excuse to get out," she told police. "I went to climb out over the top of him but I couldn't. One of my legs was over them to climb out. I couldn't and I don't know why."

Eventually one of the men "grabbed her waist" and had sex with her, she said. She froze when she realised what was happening.

Afterwards, she picked up her clothes and left the room, crying, without saying anything, and was picked up by a friend.

A few days later she messaged both men. Both apologised for "how she felt". Those messages were provided to police.

In their statements, taken a week apart in April this year, the men said the girl didn't say anything to raise alarm bells. They said she asked for two condoms, which they took as an indication it was okay.

The man accused of raping the girl told police she was "into it".

"This was shown by the way [the complainant] was interacting and touching them and the fact she asked for the condoms. She didn't say anything else and was making sexual noises," he said.

However, the complainant said she didn't recall asking for condoms.

She says she felt, in the end, all her evidence was dismissed. "They missed my points from the start," she said. "Police believed them over me."

A campaign about 'no'

Kathryn McPhillips, executive director of HELP Auckland, said the case was yet another example of why New Zealand needed a culture shift around sexual consent.

"We still have a culture in which generally a person pursues sexual intercourse unless the other person communicates successfully that they don't want it," she said.

That was highly problematic as it relied on the person being pursued to be able to show strongly they didn't want sex - which could be compromised by fear, impact of alcohol, and social context.

"This latter is particularly strong if people are from the same social set – you don't think that they will really rape you, so try to deal with it "nicely" to preserve relationship and then they hold you down and it's too late," she said.

"This situation reminds me of an old campaign about "no" – I'm washing my hair means no, I've got a headache means no. Today we might add to that, I'm more interested in texting my friends means no."

McPhillips said ideally a cultural change would be supported by a law change around "reasonable belief" - so that it was no longer a defence for an alleged offender to say they honestly believed the person was consenting.

The girl's parents have already written to the police about her case, and will support her complaint to the IPCA.

Her father was particularly incensed it took five months to interview the suspects, but within two weeks he received two warnings from police for posting about the alleged rape on social media.

He said he felt at the time it was the right thing to do.

"I told the detective, but what about the second girl? How are police going to feel if there's a third?" he said. "We just wanted it out there."

The girl's mother said she had been left with the impression detectives had simply "gone through the motions" with the investigation.

She was concerned that without police action, the men would continue to have a sense of entitlement to prey on young women. "These boys need to be made to front up and be accountable to these girls," she said.

Mainly, however, she was heartbroken for her daughter.

"It's really very sad to see her so disillusioned and angry with the justice system," she said. "There is no sense of justice for her."