Cell c Network failures

I bought a J1 and a Huawei MediaPad T17.0 at Cell c in Jabulani on the 14th of November 2015, The internet does not work on both phones I tried going there on the 18th of November to get assistance but even the agents did not know why the internet of the phones were so slow, I called the 140 help line the gave me instructions to try and fix the network operations problems, I am really disappointed I feel really angry because what is the point of having a phone if you cannot even use it, I'm really angry