Unfairly treated by cell c store/customer service

I took a contract (laptop n router) with cell c in 2020, my contract was supposed to end in July 2022. Cell C never debited from my account on date agreed upon I would contact them each month to remind them. Last 5 months before my contract ended I payed via EFT now they don't Wana allocate my proof of payments to close my contract. I scanned and emailed all proof f payment but they only give me different reference numbers, I even went to cell c maponya but no assistance. Now they keep sending me statements for me to pay am afraid they want to blacklist me. Each time I call customer service they ask that I email proof of payments the only send refference number for the case. I really don't know what to do I asked them to send me their customer service address they refuse, also asked to speak to the allocation department they refuse and promise to assist me. Please help