Network issues

I have a sim only contract with Cell c. I haven't been able to use the sim card since Friday the 9th of April. when I called I am told the sim card is okay however i should change some setting and everything will be fine. I have tried everything and really it has been frustrating because I don't have internet access whilst I need to pay. I called to cancel and and spoke to a lady by the name of Promise and she asked for my name and cell number but then cut the call. I don't want anything to do with cell c. i want them to cancel the stupid sim card and stop the debit. cell number at fault ***. my number is ***