MTN Please help me

I am desperately in need of help. I have now been battling MTN for 3 months since I first discovered ***** amounting to in excess of R13000 on my account, through 2 ******* contracts that were opened on line in my name which I know nothing about. I have tried using their whatsapp, it doesn't work. I have tried using their app, it doesn't work, and when I go into it, without putting an OTP in, it sends me an SMS saying I am now logged in. When I phone the ***** line, they tell me they have a backlog and will get to it when they can. I keep asking them to send me invoices and statements by email, on whatsapp and on the phone but I never receive anything. I have tried everything. Please, please, please, if there is someone out there that can help me get MTN to fix this, I will be forever grateful.