No service for Telkom mobile for 2 months.

I have a co tract with Telkom mobile which should enable me to make call, and use data. <br> For the past two months I haven't been able to make a call, receive a call, send sms's and only have very limited signal. The only time my phone functions properly is when I am in a wifi zone. <br> <br> I have called the call center over 10 times to try get help to fix this problem and no one has been able to assist me. I have been to a Telkom store 4 times and they have been very unhelpful. (On one occasion I was recommended to replace my SIM card which I did, but that didn't solve the problem) <br> <br> So for two months, I have been paying my monthly installment and j haven't receive the service that I pay for! <br> What do I do? I need to cancel the contract so j can get another one which allows me to communicate.