Poor response to ***** on my account

I was a victim of a ********** transaction where someone in the Vaal took cellphones on my name. My account was debited with just over R3000. When I found out, I gave them all the documents they needed. This was on the 2nd of March. Since then, I have not received any feedback. When I called the call centre, the agent hung up on me. The service I am currently receiving from MTN is disgusting to a point where I want nothing to do with them anymore. I've been a client of theirs for almost 8 years and this is the service I get?