Gordon Ralph (81) was contacted by his telephone provider, Slingshot, last week, inquiring whether he still wanted to cancel his account.
He was told the company had received a signed, typewritten letter from Mr Ralph, and it was checking to see if it was a bona fide request.
The family asked the company to release the letter.
That February 13 letter, complete with his account details, claimed Mr Ralph was ''moving to another city'' and no longer required the account.
''If you could action this cancellation as soon as possible, I would appreciate it,'' the letter noted.
It was signed Gordon W. Ralph, but ''that is not my signature''.
''That is a horrible thing to do to someone,'' his daughter, Carolyn Tucker, said.
Her father had undergone a heart bypass and valve surgery and it was essential he had access to a phone, she said. The family had not received the February account and it appeared someone had opened his mail and then forged his details, she said.
The matter had been referred to police, who were making inquiries.
