Mtn review

I bought two SIM cards which was supposed to have data and airtime in 2020 I tried to use the SIM cards but there was no data nor airtime in them. In 2022 I tried to take a loan which I failed because I was told in the bank that I am blacklisted by MTN. They sent me a message that I owe R1175 which I paid in the bank I called and went to the office to cancel the contract they failed to do so I still have proof of payment with me . Please help I want my credit record to be cleared.