cancellation

I am wondering if you can assist me. My contract ended in December 2022. I called in in December to let them know I would like my contact to be cancelled. It was not done. I paid the month to month rate of R300 and something because my phone was now paid off and I called again in January to cancel. Again it was not cancelled and I called in again. Where I was assured the contract was cancelled. You can pull up my record and you will see that I called in.

Today I got a call from NBD saying I owe Vodacom over R2000 and I would like to know how that is possible if my phone is working on a prepaid basis. I work in a bank and I cannot afford to have a bad credit record, so this needs to be resolved. I would like to know why my request was not processed and then where does this R2000 come from? I