REFUSE TO REFUND MY MONEY FOR A DEFECTIVE ROUTER

I was ****med by MTN They gave me SIM card and router on line It was delivered within 24 hours I the package never worked I call them everyday for period of a week but still the package was still not working Within seven days I returned the package to MTN store I have never used even one gigabyte or megabyte To my surprise an amount of R761.00 was debited from my account When I call they said I made a deal. I was not have the problem with that but I am not happy to pay this huge amount of money for something that I have never used. When returning the package at MTN store I made sure that the contract was cancelled. Because MTN is run by mafias my money was still debited I need my money back. People be careful with the offers and contracts that this ****** are making and promising MTN Reverse my money