A customer who had ongoing problems with his wireless broadband connection eventually decided not to pay for the service.

The man had intermittent connection issues and said when he tried to raise the issue it was exacerbated by poor customer service and difficulty reaching the provider's technical team.

He said, after months of unanswered questions, he decided to switch to a new provider and refused to pay for the months where he had had little or no service. He also refused to pay an early disconnection fee.

The provider was not happy and forwarded his bills to a debt collector.

The man, who has been identified only as Doug, eventually took his complaint to the Telecommunications Dispute Resolution service (TDR).

In TDR discussions, the provider acknowledged Doug's connection and customer service issues. Doug confirmed he had old bills that the provider was entitled to require payment for. The two parties reached a mediated agreement.

It is one of a growing number of complaints received by TDR, which deals with issues that cannot be resolved by the provider and customer directly.

TDR received 1341 complaints and inquiries in the first half of this year.

That is compared to 2269 in the whole of the 2018 financial year.

Vodafone was the most complained about provider, with 0.42 complaints and inquiries per 10,000 mobile connections in the second quarter of this year, and 5.76 complaints per 10,000 broadband customers.

Spark, which has 43 per cent of the broadband market, had 1.06 complaints per 10,000 broadband customers.

The number of complaints and inquiries received by the scheme increased between the first two quarters of this year.

Billing and customer service complaints were the most common, at 37 per cent and 27 per cent of all complaints, respectively.

Complaints about customer service were up 71.2 per cent compared to the same time in 2018.

Consumer NZ head of research Jessica Wilson said refusing to pay a bill was a legitimate protest strategy in some situations.

She said if people were getting a service that was clearly not of acceptable quality and not as described, and they had had no success seeking resolution, they could refuse to pay the portion of the bill that related to the service they were not getting.

"You'd have to make the reasons for the dispute clear."

TDR noted that in some cases a billing problem could have wide-reaching impacts.

One customer changed providers at the end of 2017 and the resulting problems with his bills almost meant he missed out on a mortgage.

The following January, he discovered bills from his previous provider had been sent to a debt collector.

The customer argued he had asked for his service to be cancelled and he was not given enough time to pay the outstanding bill before it went to a debt collector.

"During their mediation sessions, it was clear that [the customer] was mostly upset about the debt collection agency getting involved," TDR said in its report.

"He was in the process of arranging a mortgage for his first home and suddenly he was flagged as having a bad debt. He didn't mind paying the amount owed to his provider but having a debt with a debt collection agency was affecting his ability to get a mortgage."

The debt was withdrawn from the collection agency on the understanding that he paid the bill.

The record was also removed from his credit history and he was able to qualify for a loan.

TDR does not identify the providers involved in its case notes.