An Ofgem investigation over firms’ customer service and complaints performance has found that no suppliers had ‘no weaknesses’ at all.

That’s just one of the findings of a review made by the energy regulator on practices followed by 17 of the largest energy suppliers.

Ofgem has found ‘severe’ weaknesses at E.ON, resulting in specific enforcement action, a Provisional Order being issued.

Moderate weaknesses were identified at 11 suppliers –  British Gas, E Gas & Electricity, EDF, Good Energy, Outfox the Market, OVO, ScottishPower, SO Energy, Utilita, Utility Warehouse and Tru Energy.

Bulb, Ecotricity, Green Energy, Shell and Octopus showed minor weaknesses, according to the report.

Ofgem says up to 50% of customers calling at suppliers’ centres give up and hang up calls as they do not receive a response.

Neil Lawrence, Director of Retail at Ofgem, said: “From being on hold for too long, to not being given clear information, or sometimes not getting through to suppliers at all, this review has highlighted that customer service is just not good enough.

“This isn’t just about the energy industry in isolation; this is about raising standards, so we are in line with other customer retail standards – getting waiting times down, making sure calls are answered and being able to give helpful information about a critical service.”

Responding to Ofgem’s review into customer service and complains performance, Gillian Cooper, Head of Energy Policy at Citizens Advice, said: “Too often we’re seeing people living in cold and dark homes, unable to have a hot meal because they can’t afford to top up their meter.

“Now, more than ever, energy companies should be doing everything in their power to support their struggling customers. People should be able to quickly speak with their supplier to get the help they need, particularly if they are struggling to access the support available to them.”