Half of people are dissatisfied with their energy providers, according to a new survey.
Customer satisfaction is at a fresh low, while fuel poverty represents a growing problem, uSwitch found.
The price comparison website's latest customer satisfaction report found half (48 per cent) of respondents were unhappy with their energy provider with more and more people suffering from a complete lack of power.
Some 6.4 million people were struggling with rising energy costs, while the number of households in fuel poverty stood at 5.8 million, the survey said.
Customers at Scottish and Southern Energy were the most satisfied (61 per cent), the research found, with British Gas and npower, bottom in all seven categories.
Half of their combined 9.4 million electricity customers were dissatisfied with overall service provision according to uSwitch.
Main suppliers have implemented 13 price increases this year and saw combined profits reaching £6 billion to date.
Extrapolating a forecast from the data, the survey found six out of ten customers (15.3 million) did not believe they were getting value for money from their supplier.
Overall, customer satisfaction levels were down an average of seven per cent year-on-year.
Ann Robinson, director of consumer policy at uSwitch, said: "The worrying thing for all of us is that whilst prices have gone skyward customer service has gone down across the board.
"It's not so much a case of energy companies resting on their laurels, as holidaying on them."