reports that more than 35,000 complaints were received between January and June, up 55 per cent year on year, the most common grumbles being disputed charges, inaccurate invoices and backdated charging.
The other big moan was about problems switching between suppliers in pursuit of cheaper deals, although the government has announced plans to force companies to complete switches within 24 hours.
Despite the continuing rise in complaints, the ombudsman said that energy companies “may have started to improve their customer service and complaints-handling procedures”.
It said that the number of complaints had been steadily decreasing since March, with 15,853 received in the second quarter, a sharp fall from the 19,456 in the first three months of the year.
Lewis Shand Smith, the chief ombudsman, said that the decrease over the past three months was encouraging, but that it was “too early to say whether this is a trend”.
Mr Shand Smith also acknowledged that the figures did not give the full picture. “There are still too many people who are choosing to suffer in silence, because they believe the complaints process is too much hassle, too costly or will take up too much of their time.”
He said that this was “especially worrying in light of the well-documented recent energy problems experienced by consumers with npower and ScottishPower”.
Last year both companies were ordered by Ofgem, the energy regulator, to improve their record on dealing with complaints or face a ban on signing up new customers.
Yesterday the Department of Energy & Climate Change confirmed plans to work with Ofgem to put pressure on the “big six” suppliers, which also include British Gas, SSE, EDF Energy and E.ON, to cut the time taken to complete a switch from the present 17 days.
The plan is part of the department’s response to the Competition and Markets Authority’s investigation into the market. In its provisional findings, the CMA found that 34 per cent of households said that they had never considered switching their gas or electricity supplier.
Households pay an average £1,200 a year for their energy, but estimates suggest that they could save at least £160 a year by switching suppliers. The CMA estimated the total overpayment at £1.2 billion.
The energy department also announced its intention to deal with the issue of estimated bills — another big customer annoyance — by ensuring that every household is fitted with a smart meter by 2020.
Lord Bourne of Aberystwyth, under-secretary of state for energy, said: “Our No 1 priority is to keep bills down for hard-working families and businesses across the country.”