Complaint, Solution Required!

Hello Peter, please can I be assisted on a route I could take in resolving a matter than I have been made aware of just recently only with no communication made from the service provider being MTN South Africa to me - I have had an MTN contract and MTN had stopped debiting my account, however I had made contact with them at the time to settle the outstanding balance. The cellphone number had been deactivated and unusable as I could not make or receive calls or anything related, instead, when making a call to my number it was stated that the number does not exist, hence I could not query it telephonically via the customer care line as I am prompted to enter the queried number. The last payment was made completely. I recently app**** for vehicle finance was left in shock to see that I have an extremely high amount outstanding by me to MTN, which I was unaware of, and this amount seems to be incurring interest. MTN used to forward through a statement of account on a monthly basis to my email address, and my email address has not changed at all, however, I have NOT received emailed statements for years from MTN and was under the impression this was done and far behind me, if I did not enquire with financial institution to look into my credit rating, I still would not be aware of this. I have gone through to their customer care line and was given an email address to their legal/claims department as they do not have a telephone number and communicate via email only (as mentioned by the customer care consultant). I have not yet gotten a response from them after numerous emails being sent. I have always been on a debit order payment plan with MTN which stopped when the contract was over. This is now negatively impacting my life in terms of my credit status being badly affected by this and I would truly appreciate this issue resolved immediately.