Telkom continues to deduct fees for product canceled

Hi, I am still being invoiced for a free me 500mb top up. This number contract expired September 2019. I have submitted the cancelation form numerous times and was promised this matter be escalated and sorted out. I requested as such a refund on the months you continued to deduct funds from my bank for a product I don't have anymore. Surely it can't be that difficult to delete that number from my telkom account?