MTN wants R15000 from me for a contract i closed 10years ago.

Hello Peter please kindly publish my review.

I had a contract with MTN about 10 years ago, after the end of contract they kept on billing me and say im owing about R1300 somewhere there,i payed and went to the shop to ask them close my account,they agreed and say it is successfully closed.everything was fine,no deduction from my account no communication myb to say i skipped payment nothing, i thought im done with MTN,10 years later today im receiving a call saying i owe R15000 and they handed me over,im still surprised because how,all these years they didnt call to say im owing they didnt try to deduct but now they say i owe they this kind of money. Please help as everyone is tired with this company.