Telco companies Vodafone and Spark have been slammed in the latest Consumer NZ survey.

The pair are the country's biggest telecommunications players, but the hardest for customers to get hold of.

Sixty-five percent of the nearly 9000 people surveyed said they experience lengthy waits when trying to contact their Internet and mobile phone providers.

Consumer NZ CEO Sue Chetwin says they also looked at whether people switch providers, but about 60 per cent of people had stayed with the same provider for five or more years.

"We think that it reflected the difficulty of switching and comparing plans and people justified that it was too hard," Chetwin said.

2degrees were given a glowing review, with Chetwin pointing out that the common perception is smaller providers do better in these surveys because they've got so few customers.

"2degrees is a very big player and it did very well, sixty-nine percent of its customers were very satisfied with their services."