Urgent assistance required

I was unemployed due to COVID. Received my monthly statements and advised I was unemployed. Once I had received funds I made payments to MTN. Now the call centre as well as the branch cannot find my accounts on their system. They advise my account is reflecting a balance of R14 000 in credit. All I want to know is what do I owe (if anything) and I also want the numbers linked to my contract to be changed to prepaid (2 of the contracts have already exceeded the 2 year contract period). No contact regarding the expired contracts so MTN is just continuing to take my money with no feedback and I am getting no feedback or assistance from any department. All the call centres refer me to option 4 but when I insert my cellphone number the call ends. I need assistance urgently as this is no form of customer service at all My contact number is ***