MTN disgusting and disappointing

I had an upgrade done with CCSI Durban in November 2020 and the products I was supp**** with was defective, the products were then returned to a MTN direct store. The upgrade was canceled and I was instructed to take out a new contract which I had done. On the 1/01/2021 MTN debted my account with the amount of R5861. 15c from January I am trying to get it resolved and a refund issued and to date no one is capable of assisting us with refund for an error that was done on MTN's. My family and I have been with MTN for years and the service we have received is completely disappointing and disgusting. If anyone has the decency to assist me with my refund please contact me.