MTN Holds me to randsom

I have had a contract with MTN for more than 10 years. This year I have had nothing but bad experiences. 1stly my wife's phone was ******, I called to mtn to report the phone ******. The responses each time if answered was the system is off line. I reported in-store and got informed that I had to do it telephonically, a note was added to my profile for someone to call me back. To date Mth wont allow the phone to be reported ******. So it cant be black listed and I couldn't claim for a new phone through insurance.<br> 2ndly I noticed my bill getting out of control calls to numbers I didn't recognize and data. I stopped using my MTN contract number and used data card of a competitor. My calls and cost have come down by 70%. I have tried to engage with MTN. Apparently I need to talk to a credit controller, but the call center cant put me through to one, why because the lines are always down and they will call me back. I have receive this response from all calls and calls through the head office as well. MTN bill me each month even though I have with held payment and don't use the network. I want to settle my account, but cant as mtn wont talk to me.