"unfixable" account

I have been struggling with MTN to fix my account for almost a year now. Every month i get cut off because of their incompetence.

Since May 2020(right after switch from old accounts system to new accounts system), MTN kept sending me notifications that my account is in arrears, which is impossible as I have proof of payment for every month. March and April I didnt pay because my MTN app showed a R0.00 balance, so I went to the MTN store in May 2020 and settled all 3 months (March, April and May). Every month i get cut off and have to go through all the troubles to get connected again. Since then I've visited the MTN store numerous times, got statements to figure out where the problem persisted.I saw on the statements that my February 2020 (Accounts system switchover period) payment didnt reflect on their system. I phoned customer care countless times regarding this unallocated payment on my account, to no avail. Eventually one of the representatives managed to allocate my payment to 3 March 2020, but ON THE OLD ACCOUNT SYSTEM!!! So they didnt transfer this payment update to the new system and the arrears balance remained the same! The next person I spoke to told me that there is no mistake on my account and that I am still in arrears to which i requested her to send me statements. When I recieved the statement, by this time I got 3 statements from 2 different people whithin this year (Old and new accounts system statements from MTN store and old accounts system statement from the customer care representative). When I studied these 3 statements, I noticed that they do not 1 say the same thing?! Does MTN manipulate customer's statements for their own benefit?? This is very concerning!! The last representative that I spoke to was very helpful, but also went MIA when i sent through the other statements I had and asked her why they were not the same.

This cant be so hard! All I Want to know is which month is outstanding so that I can send the proof of payment!! Why does a simple question like this not get answered for almost a year now!!