Frustrating Cell C poor service - I want to cancel

I am very frustrated by constant calls from Cell C telling me that I did not pay them in September. I paid on the 02nd September 2024 via ATM to their account number. Call Centre said I must go to Cell C store to provide them the proof of payment (POP). As per their instruction, I went to East Rand Mall the next day and gave them the POP. The salesman took the POP and said he has emailed it to certain department to trace my payment. It has been weeks and I am being harrassed by Call Centre consultants' calls all of them saying I owe them. I have sent POP to ***, went to Cell C store again on the 24th September 2024 but all was in vain. When I ask for a settlement as I want to cancel I am given a run-around. All of these efforts cost me time and money but have proven to be fruitless. I had to endure a long embarrassing call from your consultant again today saying I owe Cell C. You are messing my Credit record and I cant want to cancel. Ref ***