worst service ever

I bought a phone on the last week of January at a store in Westgate after two weeks the phone started giving me problems. On the 23rd of February I took the phone at Cell C's head office near Woodmead. I was informed that the phone will be back after 7 working days, after 8 working days without getting any communication from them I decided to go check the phone and I was told that it's not ready, I have a good mind of cancelling the whole contract and go buy the phone else where, this is very bad service, I bought that phone for business purposes and now I'm left stranded and Cell C dose not even care to update me. The phone is 2 months old and I'm a new customer to Cell C but the way this situation has been handled I think I'm going to cancel my contact if my phone is not back by Wednesday.