I HAVE BEEN **********, POOR CUSTOMER SERVICE AND MY CREDIT SCORE IS AFFECTED

I took an MTN Home WIFI Router contract in January 2023. The router has never worked. I contacted MTN several times about my issue but I never got assistance. I Visited the Acornhoek branch and the Hoedspruit branch several times with the router but I also never got assistance. I paid the router for 3 months without the WIFI working, I had to stop paying in May 2023 because I was paying for a service I wasn't receiving, I contacted the MTN Legal team and they also didn't help me. I even sent out an email to Lonwabo Fatyi MTN Internal after a call explaining my situation with the WIFI now the account has been handed over and they are demanding that I pay a ridiculous sum of money which is really unfair. MTN has failed me decimally so. they failed to fix my connection issue even though the sales lady who sold it to me said it will work just fine in my location. how am I expected to pay R4 000 for a WIFI router that I never used?