'Free' broadband provider Orange was bottom of the list for the second time running. More than a third (35 per cent) of the 10,500 respondents said they were dissatisfied with the firm's broadband service.
TalkTalk, the 'free' Carphone Warehouse broadband service, followed closely behind with 31 per cent of its customers unhappy with its service, the uSwitch.com home phone and broadband Customer Satisfaction Report revealed.
Overall satisfaction down
Across the board, customer service satisfaction was down by 3 per cent since October last year, and 10 per cent since March. A quarter of broadband customers said they were dissatisfied with their ISP.
"Unlike last year's survey when providers were in many cases simply overwhelmed by demand, this year the problems are more technical," said Chris Frost, communications expert at uSwitch.com.
"New advances in broadband technology appear to be having an adverse effect, with connection problems and service interruptions occurring all too frequently and customers having to make numerous phone calls to get problems fixed," Frost added.
"We acknowledge the findings of this survey but moreover listen to our customers and as a result, are aware that some of them have experienced service and technical issues over the past few months," Orange responded in a statement. "We apologise to those customers who have experienced problems.
"We are taking steps to improve our network capacity and customer services, including investing heavily in our teams and will continue to do so. Our focus is on getting things right for our customers and we shall continue working to improve the levels of service we offer," Orange added.
TalkTalk to make improvements
Carphone Warehouse , TalkTalk's parent company said in a statement: "We have recognised that we need to make improvements to elements of the TalkTalk broadband customer experience."
The message from uSwitch.com is for broadband firms to do - rather than talk about what they're doing. "Our message to broadband companies is to stop telling us what you're doing and actually start doing it. Customers are entitled to the best of both worlds and should not have to choose between price and service," Chris Frost said.
Plusnet customers were most satisfied, with 78 per cent of happy customers, followed by AOL , Sky and Virgin Media , all with 76 per cent customer satisfaction rates. Sky and Virgin Media featured in the uSwitch.com survey for the first time.