Poor understanding of good customer service and widespread confusion about the billing process is why many customers do not trust energy suppliers, according to Consumer Focus.
Adam Scorer, director of external affairs at the consumer rights group, wrote about the problem for moneysavingexpert.com.
He said the main issue among consumers is the feeling that energy prices are unfair, with watchdog Ofgem compounding that impression with its announcement that companies are quicker to raise prices when wholesale costs are up than it is to cut prices when costs are low.
Mr Scorer argued that the mistrust is down to the way the market has evolved, with smaller energy suppliers having little opportunity to enter the market and "put the wind up the Big Six".
He called for a review into the structural problems in the market.
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