Ofgem said it had been assured by E.ON that all of the consumers affected had been identified and would be contacted and sent a rebate of an average of £14.83.
The amount includes 8% interest on the amount they were incorrectly charged.
More top news
Some students argued that the centuries-old tradition of wearing gowns, suits and mortarboards to exams was 'archaic' and looked elitist.
Clear spells in the north overnight where it's actually cold enough in the north for a touch of ground frost. Further south cloudier.
Grange Hill actor Terry Sue-Patt, who played Benny Green in the long-running school-based drama, has been found dead at his home in London.