An elderly couple from north Devon have been shocked to get two bills for nearly �900 for gas from a company that does not supply them.

Harman and Mona O'Hara, from Bideford, first received a demand for payment of �850 from Npower, despite being loyal customers of British Gas.

After being reassured that the bill was a mistake, they then received a second bill for �870 from the firm.

Npower has said it will investigate why the O'Haras' property is listed on its books.

Imagine getting a bill addressed to the 'top floor flat', with no name. It's incredible

Mona O'Hara

Mr and Mrs O'Hara have lived in their quayside flat for more than 30 years and have used gas for all of that time.

They have always been supplied by British Gas, as 82-year-old Harman used to work for the firm.

They also said they had never even spoken to a representative from Npower.

Mr O'Hara said of receiving the first demand: "Well, it was very worrying to get a bill of that size."

At first, the O'Haras' daughter contacted the firm and was reassured that it was a mistake and the bill would be eradicated from the company's computer.

The couple then received the second bill at their address.

N-Power could not offer reasons for the bills

Harman O'Hara said: "The big worry is that if they carry on with this, they might take out a county court summons.

"That would blacklist the whole property and other people would suffer from it."

Mona O'Hara said: "How they got this address is beyond me. They don't even know our name.

"Imagine getting a bill addressed to the 'top floor flat', with no name. It's incredible.

A spokeswoman for Npower said they had been unable to offer any reason for the bills.

However, the firm said it would contact Transco, the owners of the gas pipe system, to find out why the O'Hara's address has appeared on the Npower books.