It was also found that the company performed better than any other supplier on complaints about sales.
Phil Bentley, managing director of the energy provider, said: "Customer service is the number one priority for us, so I'm delighted to see that the effort we have put in is making such a difference."
He added that "there is no room for complacency" and the company will continue to work to improve its service.
British Gas recently revealed it is planning to reduce the carbon intensity of its electricity by a further 11 per cent by 2020.
The company stated that at the moment, its electricity supplies are already greener than the rest of the UK's other major firms.
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