Cell C
Overcharging but no one does anything!!

I have sent a few emails on cell C's website - ONCE someone returned my call and the call dropped - NEVER BOTHERED TO CALL BACK AGAIN!!
Upgraded my contract - was supposed to get 100mb free with the deal and another 500mb free with the bbm lite plan. OVER AND OVER i am not being given my 600mb free per month and am being charged for my data usage - my bill has increased considerably because of this and i can not afford bills like this!!! Why am i being charged for something i am supposed to get free? Where are my 600mb i am supposed to get??
I want this rectified and my credits given or i will take this up higher with an ombudsman to have this whole contract cancelled due to the fact i am not being given what was sold to me - total decption and breach of contract!!
Please Cell C - assist me as i am a paying customer and only want what was promised and sold to me!!!