British Gas has apologised to a disabled man after his electricity and gas supply was switched to its tariff without his permission.

David Parrott, of Lake Close, March, says he has used rival company E.ON for years because he feels it offers the most competitive rates.

He said: “I live on a tight budget so I pay £40 a fortnight and that usually covers the energy bills.”

But his account was accidentally transferred by a household in a nearby new build in October, and bills of almost £400 from British Gas arrived and what he thought to be a debt collector was at his door.

Even after he thought the issue was resolved, another letter arrived last week saying he was back with British Gas.

Mr Parrott said: “I’d been trying to sort out the situation, and even had someone at the door chasing me for the payment.

“I had a good system in place with E.ON before and this mistake is costing me. I don’t want to be debt to anyone and this isn’t my fault.”

A spokesperson for Centrica, the parent company of British Gas, explained it had received a request to take on the account for a neighbour on Lake Close.

But, it admitted, Mr Parrott’s supply was taken over by mistake and the follow up letter was an admin error.

While the gas was closed, British Gas failed to close the electricity account.

The spokesperson said: “Our normal debt process continued which resulted in a visit by a representative on behalf of British Gas.

“This visit is intended to check there hasn’t been a change of responsibility or if there’s any vulnerabilities in the household.

“We never instruct bailiffs.”

She added: “We’ve closed the incorrect account and would like to apologise for the concern our error caused.”

Ofgem, the regulator, said an energy company should check the customer requesting the transfer is connected to the property.

If a customer contacts their supplier to say an erroneous transfer has happened, suppliers should resolve the issue.

An E.ON spokesperson said: “We’ve now started the process of taking this account back and we’ve spoken to Mr Parrot to reassure him that he will come back as an E.ON customer as though he never left us – on the same tariff as before and with no payment due to British Gas.”