A long, cold winter and rising fuel prices mean lots of big gas bills have been landing on doormats this month.
But spare a thought for Pizza Parlour in Belgrave Gate, Leicester, which has had a bill for about £24,500.
Owner Illesh Amlani arrived at work to find bills demanding back payments.
He said British Gas told him their staff had been misreading the meter at the shop since 1995 and now wanted him to re-pay the difference for the past five years.
"I couldn't believe it," he said. "This is a very small business and I can't be expected to pay for their mistake like this.
"I never gave them a single meter reading – it was always their people coming round and taking readings and they got it wrong.
"It's a six-digit meter but they only read the first four digits, so I was paying only about £30 to £60 a month."
When Illesh bought Pizza Parlour in 2005, the accounts from the previous owner showed the low cost of gas, but having never owned a restaurant before he had no way of knowing the building was getting such a discounted rate.
Illesh has already suffered the effects of British Gas now taking the correct readings, which has upset his previously sound business plan.
He said: "Now I'm paying more like £360 a month for the gas I'm using, and that's obviously a lot more than I ever expected to be spending on gas.
"I'm still negotiating the back payment, although we seemed to have reached a deadlock."
Since the initial demand for £24,500 in November, Illesh has managed to argue that as a "micro business" he was only liable for under-payments for the past three years under law.
That reduced the bill to £13,700, but Illesh still refused to pay. The company is asking him to pay £9,000 over two years but he is standing his ground.
He said: "I've offered them £50 a month extra until the £9,000 is cleared but they haven't accepted that."
A spokeswoman for British Gas said: "A discrepancy between the meter at Mr Amlani's property and the details held on the industry records mean we have under-billed his business for a number of years.
"We have recognised an error was made and under the Back Billing Code have only applied the correct charges for the past three years, as well as applying a goodwill gesture to further reduce his bill.
"It is important Mr Amlani pays for the gas he has actually used over the past few years, as otherwise these costs will have to be born by other customers."
