Mtn no connection

I have a contract with mtn for 3 years now I always pay. My problem is from Tuesday I am not connected and I have paid. When I call them everyone from client service they lie and say they traffering me, their service it's very bad, there is no customer service, I got connected for 30 minutes and it disconnected again. Till now I don't have connection. I want to cancel and get a better service provide, this is not my problem. I now have to buy data k top of my monthly debit