Lack of information, slow response to complaints, pressure from suppliers and inexperienced staff also dissatisfied business customers.
The research polled customers of British Gas Business, EDF Energy, Npower, Powergen, Scottish and Southern Energy and ScottishPower.
Representatives of the suppliers have met shadow minister for enterprise Mark Prisk MP and the industry regulator Ofgem to discuss a better deal for small businesses and a shake-up of industry practices.
It was revealed that although 78% of small business owners consider their bills to be overpriced, fewer than 10% changed suppliers each year.
Philip Davies, director of Ofgem, said: "Being a passive customer means that, as the years go by, you are much less likely to get a better deal than an active customer."