RETENTIONS TRAUMA

I had an MTN sim contract that was set to expire in October 2021. The contract was being paid every month without fail. In August I first contacted retentions to know when I needed to terminate and they stated in October 26, 2021, which I then sent an email to request this. They never got back to me and in November they debited the amount plus about 50% extra. I disputed and won, sent emails again, no response. They responded in December. I spoke to Nancy who said she canceled everything. January, they called stating I owe R500 which was double what my contract was, I explained the situation and was again transferred to retentions who said their systems were down so the cancelation didn't happen but they would do it then and ask Nancy to call me and confirm in 48 hours, nothing. Now, almost a year later, they sent me to collections for R1200 they say I owe. When I try get this resolved, they give me run arounds and say they have passed credit on my account and for me to wait to have it closed. This was beginning of September, and I have proof. I am still waiting! Please help me!