Terrible Service and Outright Theft from MTN at Liberty Midlands Mall

Even 1 star is too much to describe the pathetic serivce received from MTN. They are theives in my opion and are quick the money of their customers for services that they do not provide. My elderly mother in law received a phone call by the mtn sales department in July 2021 and they sold her a phone. Two months had past and she did not receive it. They were still debiting her account in the mean time. Eventually the phone had been delivered in October 2021, by which time she had cancelled with MTN and taken a contract with VODACOM(Excellent service just by the way). She then proceeded to return the phone to the MTN Store at Liberty Midlands Mall and cancell the contract. Little did she know up until now they were still debiting her account. When I had relised this, I immediately called MTN and spent over an hour on the phone being transefered from department to department without assistance. I then went with her to the same store. However no one was able to assist with either stopping the debit or locating the phone. It was clearly shown on their system that number was not in use for this period yet still no assistance was received, Even now I am going back and forth still trying to reslove this issue. How is it that a phone was returned and no one bothered to query where and who it belonged to?