Cant call on CellC

I have reported not being able to make and receive calls numerous times with cell C customer care. Each time the case is closed without any effort to resolve the problem. Clearly cell C is unable to assist. Now I am stuck in a useless contract, still unable to make and receive calls! Worst mobile service provider!!!! No concern with customer complaints and problems!!! Incompitent call centre staff!!! Worst network and services!