Worst service from MTN

I'm still waiting for direct response from mtn till now. I have experienced ignorance,and attitude from mtn festival mall, call center, repair center and have been **** too as well by the stuff. Modise from head office no longer respond to my emails, I haven't been harsh to them but only require about my phone. I have lost a lot already due to this phone, all I need is to pay for something I will b using not in repair center. I have asked if someone would use through phone so as to experience the problem first hand but all I get is the phone has no problem which means that i'm a mad person who doesn't know what she's saying. I got the phone end of November 2014 but since January the phone is in repairs. The phone has a physical scratch but now it's worst and they will rub it on me I know. All I get is we are sorry and losing 1 customer won't affect mtn and they will black list me if I stop paying, mtn has a way of getting away with it. How can a new phone be in repairs 8 times and they say there is no problem? Is it that they don't want to admit that they can't fix it or they need a bribe? I might be an under dog and the one who is losing but bribing is not going to happen.