Bad service ever and ripoff

I received a phone call from one of CELL C agent telling about the special they have, because I wanted a phone I agreed to take one and they told me that I qualify. after few days the phone was delivered but it was faulty then I called them ,they promise to collect it they never came, I don't know how many times did I call them they just never came, then I decided to reverse the money they been deducting from my account , they went back and deduck it again twice but they did not come and fetch the fone, I called the before 7 days I don't know what to do , they been deducting my money since June 2017 for the fone which is not working they are ripping of, I can't trust CELLC anymore their service is so bad how can they do this to me.