Angry customer very poor and disappointing service

I am highly disappointed with MTN service I app**** for wifi router in June and they deducted about R600 to my surprise the whole month i was taken pilar to post trying to get it activated until end of month i paid for nothing. I took it back to mtn limpopo mall plk assisted by mahlo r. On 24 July 2024. He gave cancelation per with IR no now I am trying to buy a house the bank is declining saying I am owing mtn which was not even a contract but month to month. Please help my name is clean but my life is blocked by a company that never rendered a service from day 1