Gas and electricity customers 'do not understand' bills
29 October 2013 Last updated at 20:28 GMT
Many energy customers do not understand the details of gas and electricity bills, according to the group Consumer Futures in Wales.
It comes as MPs have been cross-examining energy bosses about their price increases.
Four of the big six companies have put bills up by an average of 9.1%.
Economics correspondent Sarah Dickins reports.