WATCHDOG Ofgem called on energy companies yesterday to take action over their poor handling of customer complaints.

The regulator’s chief executive has sent letters to the big six and smaller and independent suppliers about the “industry-wide failure” to handle complaints to an acceptable standard.

It follows research by Ofgem that found more than half of those who had complained — 57 per cent of domestic customers and 52 per cent of small businesses — were not satisfied with how their supplier handled the problem.

In almost half of cases where the supplier considered the case resolved, the customer did not.

Ofgem said satisfaction had fallen particularly with Npower and Scottish Power — from 36 to 21 per cent and from 44 to 20 per cent respectively.

Earlier this year Ofgem opened an investigation into Npower’s “prolonged customer service failings,” the first under its new standards of conduct which state that suppliers must treat consumers fairly.

Citizens Advice chief executive Gillian Guy argued consumers deserve better, considering “energy prices are up by a third since 2010 and people are now paying well over £1,000 a year to heat and light their homes.”