A lack of competition in telecommunications in New Zealand has led to complacency from the industry's two biggest players, Consumer New Zealand says.
A new survey from the organisation shows internet and mobile companies struggle with the basics of customer service.
Spark and Vodafone were rated as having the lowest level of satisfaction among customers. Both companies scored comparatively poorly when it came to value for money as well.
Consumer chief executive Sue Chetwin said they had a bit more competition these days.
"The rivers of gold for them aren't quite what they once were, but, that said, they are big and as long as they sort of maintain their presence they don't need to worry so much as they should about the smaller ones," she said.
"That's why I think it's really important that people know about the other players and that they can make comparisons."
Ms Chetwin said of the seven internet companies in the survey, Flip was rated best for overall satisfaction.
On Sunday, Spark customers took to the provider's Facebook page to complain about problems with calls, texts and internet service.
Some said they called Spark's helpline for answers, but waited on hold for hours.
It took much of the day for broadband and mobile networks to be restored, but data issues lingered.