Incorrect Package Upgrade

I was called by Cell C to say I am due for an upgrade a few months ago, we agreed on a package which included 75min and 1.5G Data and a Z3, I received the phone and the upgrade took place however I am only receiving 50min and 1G data per month. I called Cell C 4 times now and was assured that someone will listen to the call recording and provide me with feedback within 24 hours, its been almost 2 weeks with not 1 call back from Cell C however when I call I get told they will mail the relevant department and get back to me. I have a REF number however nobody seems to assist and it is becoming frustrating. It is clear why people don't mind paying a little more and being with Vodacom as the service is far more important than the cheap contracts offered. I am still waiting for a call to tell how why I am being ****** with the incorrect contract. ***