Bad service

I made a payment in the MNT Wonderboom branch on 30/12/2023 , I was assisted by Kgomotso Malete. I then went to the Centurion branch to make a payment on 31/01/2024 I was then told than my account is in arears for the December month. The Centurion branch manager loggen a ticket for the payment to be allocated on my account. MTN then suspended my line claiming that my account is in arreas. I then called the 135 number and I was told to go back to the store where I made a payment for them to allocate my payment, but no one answers the phone when Icall the branch. Even the branch manager at the Centurion branch by the name of Sazi Mkhutshwa puts my calls on hold till I hangup. MTN declined to cancel my contract alluding that it is in arears.