SMS messages to pay account

Receiving constant sms messages that money is owed on a Telkom account that was settled in December last year. Telkom have confirmed that the balance is zero, as have some members on the call centre at NuDebt (Anne and Phulani). Yet the SMS's continue...<br> <br> When following up with the call centre the answer is always \we will contact you later to confirm\". Nobody calls back.<br> <br> Please close off any info you have on this account urgently as it is paid, and ensure that no more incorrect SMS's are sent out. Thank you."