Double debit while I have paid

I am very unhappy with the customer service. I made a full payment on the 12/11/2020 of may outstanding balance and was told to send an email of proof of payment to Ismahil Makgeta, which I did. my account was only updated with a function of the amount that I paid and i keep getting messages that the balance (which I paid) will be debited from my account month end. I called the call Centre countless time and the call just keeps getting dropped... VERY UNHAPPY