The country's major power companies - including Trustpower - have rated poorly on a New Zealand customer satisfaction survey.
An annual Consumer NZ survey on power companies found just 45 per cent of power customers were satisfied with the service they received.
The five big power companies - Contact, Genesis, Mercury, Meridian and TrustPower - still hold the lion's share of customers. However, Consumer NZ chief executive Sue Chetwin said the survey showed the companies continued to be "perennial laggards" when it came to customer service.
"This satisfaction rating is lower than rates we've found in the banking and general insurance industries," she said.
"The big players are letting the side down."
Trustpower responded in a written statement, saying it aimed to provide excellent customer service "and we continuously strive to improve our customer's experience".
"We are excited about the plans we have in place to improve customer experience and take heart that our internal survey is showing that customers are recognising and that improvement.
"Trustpower has long established relationships with the majority of its customers, we also note Consumer calls out that some of the newer retailers are yet to be tested."
Bosco Connect, a subsidiary of Mercury Energy, was singled out as a particularly poor performer, with a customer satisfaction rate of 28 per cent. Thirty per cent of customers with Bosco had regularly experienced long wait times to speak to a customer service representative.
At the other end of the survey, 71 per cent of Flick Electric's customers said they were very satisfied with the company's service.
In a statement, Mercury Energy said it was surprised and disappointed at the survey results.
"We survey over 5000 Mercury customers each year (vs the 218 in this survey) and the Consumer survey results differs hugely from our own feedback from our customers.
"Our customers consistently tell us how much they value our Free Power Days, Airpoints dollars, Good Energy Monitor and all the other unique benefits Mercury provides and our low switching figures support this level of customer satisfaction."
Contact Energy's Shaun Jones said it worked hard to provide customers with a great range of plans and ways to get in touch, "so customers can choose the combination that works best for them".
"We're always looking for opportunities to improve and we use the feedback we receive from our customers every day to help focus out efforts."
Other statistics of interest to come from the survey included that 30 per cent of customers deliberately cut back on heating in winter, blaming power prices; 18 per cent had had problems with incorrect bills; 38 per cent had encountered long wait times on the phone to talk to a customer service rep; and 21 per cent said they received unhelpful service once they got through.
A Meridian Energy spokeswoman said it was disappointed to hear that 9 per cent of customers in the survey said they'd experienced unhelpful customer service with them.
"We'll certainly look to the survey findings in detail to identify any improvements we can make so it's as easy as possible for our customers to manage their electricity with us."
Genesis Energy were unable to comment before publication.