Sinn Fein councillor Patricia Logue
And she has asked the company how widespread the problem is and what steps they are taking to rectify the situation.
Said Councillor Logue: “I was contacted by a number of constituents who felt that they had been overcharged on their gas top up meters.
“When they queried this, it was subsequently found to be the case and they received refunds which has to be welcomed.
“Following these concerns being raised with me I got in touch with firmus and asked that they investigate the scale of this problem in Derry and that they put in place measures to rectify the situation as quickly as possible.
“And if any customer has overpaid that they should be credited straight away.
“Fuel poverty is prevalent for many people, and as I represent an area of high deprivation its vital that customers have piece of mind and our clearly not left out of pocket,” she added.
