Requested MTN to end my contract and still billed

In 7 May 2015 followed up with MTN about my contract I requested Nashua Mobile to end.I was informed by Nashuamobile that after my payment of R7606 the contract was ended.I contacted MTN customer/accounts and could not go through I send an emailed to [Email Removed] on 07 May 2015 Nthabeleng Molefe responded through an email on 22 June 2015 requesting that I email her the completed form and copy of my ID. I did so, I followed up on 25 June 2015 and requesting confirmation letter that the contract was cancelled.I did not get any response.7 July 2015 I followed up [Email Removed] and no feedback.At that time MTN is billing monthly fee of R1063.32 and the numbers were deactivated in 2014.I notified MTN and I no longer use the numbers.The amount is accumulating now and its up R20 000. When I requested if the account can be closed so that I pay the balance. I am told that the contract can not closed because I must pay the balance. I made arrangement to in monthly instalment to pay off but how will I finish the balance if billed monthly? None of these officials from the legal could assist. Zola Matshoba,Tshepiso Moletsane,Nwabisa Mjokovana ,Unathi Njozela,Ntsudzuluseni