Disappointing service Cell C

I opened a new contract: 18/08, with Cell C, received my handset and tablet, after taking a few weeks to figure out how Cell C works noticed that the tablet keep requesting Insert Sim, took in to Cell C East Rand Mall on the 19/11 to have it repair/replaced, they send in out for repairs (I was thinking) went back on the 05/12 to enquirer and no one knew where my tablet was, received a call on the 30/12 with a quote of R1300 to repair for the tablet, which i hardly use to be repair, even on my statement my monthly data doesn't get used and I need to pay this amount to have it repair when i asked why they just told me its the motherboard, now i would like to know, if this is the way Cellc does business with new clients, I had to call to find out about my tablet, I feel like cancelling this contract handing Cellc back there damaged handset, and going back to MTN, I'm paying monthly fees for a tablet i dont have and they not refunding me my data and neither do they want to fix this tablet which has being with them since November.