Norman Bissett Complain

I get mails from Norman Bissett for payment on Nashua mobile. It is on a Vodacom contract 14 years ago. I cancelled the contract 14 years ago but lady did not cancelled the contract. They phone me 6 months later to tell me I need to pay the money, I did pay the outstanding balance. Now 14 years later norman bissett try to get the money again ather I did pay it. They can not even give me the original ref number that I can trace the payment. I phoned the bank to try and pull bankstatements. Bank told me that the cannot give me statements from 14 years ago.