Fewer than a third of energy consumers who complain to their supplier are satisfied with the response. This is a pretty thorough indictment of customer service in the industry.

A survey carried out on behalf of regulator Ofgem has found 57 per cent of customers were unhappy with the way their complaint was dealt with. Just 32 per cent said they were satisfied with their company’s response.

While this is an increase on a survey two years ago when the equivalent figure was 27 per cent, Ofgem says complaints performance is “unacceptably low”.

Some customers of course, will simply be wrong. Their complaint may be unfounded, and therefore some will always remain unsatisfied with any outcome.

But the majority of concerns expressed were not about the outcome. It is after complaints are logged (a stage most consumers seem happy with) things start to go wrong. Firms take too long to resolve them and a lack of communication means customers are left in the dark (figuratively, that is) for lengthy periods.

Scottish Power is highlighted – Ofgem is already investigating the company’s customer service and is to extend this probe to take in complaints performance. True, the company is one of the most improved since 2016 in this regard, but that is against a pretty low bar.

Energy UK chief executive Lawrence Slade says wider roll-out of smart meters will mean more up-to-date meter readings and more accurate billing. They will certainly make energy bills – notoriously confusing – more transparent. But Mr Slade misses the point if he thinks this will obviate the need for the Big Six and their competitors to sort out their performance on complaints.

Many customers feel powerless in the face of the energy companies, which would do well to note that one of the most powerful factors influencing whether people were satisfied with the outcome of a complaint was a simple explanation of what had gone wrong. This really should not be too much to ask.