Horrible services from MTN

My name is Agnes Rink. July 2021 I bought a router online,then I received a home router instead of pocket router. So I was told that if I return it before 10 days of purchase, it will be canceled. So I returned the router the following day,after receiving it to the nearest MTN branch at that time in Matlosana Mall. I was given a reference number(IRMS 517503) and told to call the customer service with that number to have it canceled...I did,but they said it was canceled,next thing I see a debit. I called again said it will be canceled. It's been 10 months,I have been debited for something I don't have in my possession,and never used. I have emailed more than 10 times,calls I can't even mention, yet what I'm certain of is that they always mention that the calls are recorded,so evidence is there of what has been said to me. I have started reversing these debits,yet now it's affecting my credit score. So now I'm considering going to the Ombudsman Office,so this matter can be resolved legally. Yet I know that this service is ruining the Name of MTN company.