ISMART BAD SERVICE

I have a cell c contract with them for the past year. 2 weeks ago my sim got canceled for no reason i phoned them apparently my sim was connected on some one elses contract wich was canceled so mine got canceled to. I asked them what now. They dont know. I have stopped my debit order for end feb and demand an answer and explanantion from them and i said i want all my money back from all the months i paid. Since today no comment and my phone is still off.