Account in arrears with R8.00 but MTN is the one responsible for debiting my acount

Since last week i have been getting messages that my account is in arrears today i received a call to say i need to make a payment to prevent disconnection of my account. I called your call center spoke to Masibulele who told me that there is an outstanding balance of R8.00 on my account. After he viewed my info it was confirmed that my account was debited R8.00 short in January 2024. I then asked to speak to a manager to understand how it is my problem if MTN incorrectly debited my account he said he is not allowed to transfer me to a manager. Then he further went on to say that our call of 19 minutes exceeded the 10 minute call mark so he will have to take my number and get someone to call me back baring in mind out of the 19 minutes i most probably spend 10 minutes holding while he was checking his system. I am a manager of a customer engagement Centre and if any of my agents had to allow a call to go out of control in this manner they will be reprimanded. Worse service ever.