Frustrated MTN customer

I bought a WIFI router from MTN in 2022. When the router arrived it turned out that my area was not covered. Mind you I had provided the consultant I was speaking to with my address before we could confirm anything else. I called them a day after to inform them about this issue and I was instructed to take back the router to my nearest MTN branch which I did and was provided with an RMS number 775733-T. I also called in multiple time to cancel the contract and was informed that the cancellation was done. To my surprise I found out this year that I have been handed over and I have a debt of over R5000.00. When I call in, I get transferred until the line drops. I have also been seeking help from their social media, but they give me vague responses and they do not get back to me unless write in.

I am honestly very disappointed in MTN as this has resulted in my credit profile being ruined. My life is on hold because of a mistake they did.