Smaller energy firms were the big winners in Which?s annual satisfaction survey from customers.
Out of the 30 energy providers rated Ebico, based in Oxfordshire, came in the top five with Octopus Energy taking the top spot.
Big names such as British Gas, Npower and Scottish Power came below number 25 in the list which was compiled from the experiences of almost 8,000 UK customers.
Ebico, based in Carterton, is a not-for-profit social enterprise which prides itself on being 100% green energy. It uses any surplus money to fund the Ebico Trust which is working to end fuel poverty in the UK.
It scored 76% overall in its customer score and received five stars for value for money, bill accuracy and customer service.
Tonik Energy, based in Birmingham, also made the top five with 76% with Stroud-based Ecotricity coming in the top 10 as well with an overall customer score of 72%.
Read more: Turnover rises sharply at Ecotricity
Alex Neill, Which? managing director of products and services, said: “Our survey shows the importance of value for money and good customer service: energy suppliers delivering both to their customers tend to be thriving, while the Big Six and other poorly ranked firms are paying the price for not giving customers what they want.
“All energy companies should be working to give their customers competitive prices and excellent customer service. If you’re not getting a good deal, you should look to switch, as you could potentially save over a hundred pounds and get a much improved service.”