Some of the country's biggest energy firms are to be investigated over claims they have been overcharging customers following a surge in the price cap.
Ofgem, the market regulator, said that there have been “troubling signs” that some companies have increased households' direct debits by more than necessary to cover a £693 increase in average bills.
Suppliers are allowed to raise monthly charges, but it must be according to the household's usage and you must be notified of this beforehand - usually at least 10 days before it goes up.
