A householder thought he had been given the bill for the Illuminations when British Gas demanded nearly £12,000 to supply energy to his two-bedroom bungalow.
Surveyor Payl Jones returned home to Poulton after working in the Lake District to find a letter from the gas and electricity suppliers on his doormat.
The letter said that because Mr Jones, 41, was using less energy than usual British Gas were prepared to change his £43.82 monthly direct debit to a staggering £974.13.
That would mean an annual bill of more than £11,600 – enough to heat his home for 20 years.
Mr Jones, of Chester Avenue, dismissed the error as a mistake but when he checked his bank balance at an ATM later that day, he discovered he had been cleaned out.
He said: “I couldn’t believe my eyes. They said I was using less gas than usual but then said they would be charging me 20 times more each month.
“I put it down to just a mistake but when I went to the cashpoint I discovered I had no money.
“Luckily, my mortgage had been paid, but it still came as a huge shock.
“I can joke about it, but something like this could have a terrible effect on an elderly couple.
“And if people are short of money they could have been left without any money to pay for food.
“As it was, I had to rely on what I could cobble together for tea from leftovers and what was in the cupboard.
“I phoned British Gas and told them what had happened but they just said I would have to wait for my refund.
“They didn’t seem too bothered about what had happened.
“The real insult was that they said the direct debit had been changed because I was using less gas and electricity than they expected.
“However, the next sentence said the bill was going up to more than £970.
“I’ve only got a small bungalow but with a bill like that I thought I was heating Buckingham Palace, either that or they had sent me the bill for the illuminations by mistake.”
Last year hundreds of British Gas customers were left hard-up in the run-up to Christmas when the suppliers took out two, or even three, direct debit payments instead of the usual one.
British Gas spokeswoman Leigh Franks said: “I’m very sorry for the mistake which we’re looking into immediately. We’re contacting Mr Jones to apologise.”
n Anyone having problems with their gas bill should contact British Gas customer service on 0800 038 0202 or tweet @BritishGasHelp