The study also found that the public are forced to try seven times over the same amount of months to get their issues with providers resolved.
Allan Asher, energywatch's chief executive, said that the report was evidence that the UK's energy companies are "their own worst enemies".
He explained: "By not listening to consumers, not returning their calls, not updating accounts and many other examples that are signals of poor customer service, they give consumers no reason to stay.
"Worse still, they allow simple problems to turn into seven month sagas of broken promises and poor customer service."
The research has come after the body also found that there has been a 64 per cent increase in customers owing £600 or more on their gas and electricity bills.
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