SHAME ON YOU CELL C

I have attempted to close my Cell C account several times. These sim cards and phones have not been in use for about 3 years. On the 5/7/2019 was my last attempt and call center explained because its the 5th I still have to pay one more month. So July I paid August nothing went off and September the debit order went off again. I CANNOT GET THIS CONTRACT CANCELLED! Just received a call I'm R100 in arrears, tried to explain I've cancelled more than a year ago. Now I'm being shouted at that maybe if I pay my account up to date they will cancel my contract. This extremely rude lady has a cheeck to SMS me saying I will be handed over!