Billing of a cancelled contract

Good Day<br> <br> My name is Melisizwe Mabuya from Cape Town and my ID number is: ***<br> 083. I had a contract subscription with MTN, which expired in April 2015. I<br> cancelled the subscription after that and the contract cellphone number was<br> then converted into prepaid. The number I am referring to is ***.<br> <br> It is a shock that I continuously receive text messages that an account I had with MTN is in arrears. A telephone call I made on,<br> 31 August 2015, did not yield any positive results in terms of good explanation<br> as I was only informed that there number is a prepaid one. The account number I<br> had when I was still your contract subscriber was A***.<br> <br> I would appreciate a response from someone who will competently tell me how it<br> is possible for MTN to send a text message after contract subscription<br> cancellation, confirming a transfer of a number from contract to prepaid, only<br> to send a message a few months later to say the account is in arrears. The<br> cancellation confirmation is in my opinion, an indication that a contract<br> account I had with your company does no longer exist.<br> <br> I hope someone from your company will be professional enough to get in touch<br> with me by responding t