Mtn is the worst and *******!!

Mtn are *****’s!!! I have a contact with them for over 4 years and paid every single month via debit order of which bank statements are there to show! 3 months ago I changed my banking details which they messed up on their system did not debit even though the account number was correct! I then ended up paying on the Mtn app to which a month later they could not even trace my payment done on the app which you think should be an immediate payment it’s done live! The next month the same thing happens no debit order runs, fund sufficient by the way. The line gets cut again for the 2nd time I then go and pay in the store only to be told after submitting everything to the internal department that I owe money dating as far back as last year! What I find so strange is that if this were true I would not have been able to use the phone it would be cut! I then submitted bank statements to them for a year and 6months proving a successful debit order went off every month! Today’s feedback from internal I owe one month now from where I would like to know? The consultant who assisted me at the Kenilworth store does not have much knowledge or insight to assist me either she just keeps giving me feedback that does not make sense first she said they I needed to pay R 2000 now it’s one month which is R 679! I am not paying a cent I do not owe and will not be ****** . I have to now have a line that is cut and cannot make or receive calls which is ridiculous all because Mtn are effing idiots!