CELL C - DOES NOT RECEIVE CALLS!!!!

I logged a complaint a few weeks back, but I have had no feedback as to what is going to be done to fix the problem. The phone still drops calls and and not all SMS's are received as well as I am unable to receive calls. This is now totally unacceptable and I therefore want to move over to Vodacom because Cell C does not work!!! This phone is used as a business phone and we are loosing business because we are unable to receive calls - This is now extremely urgent and expect this to be resolved today!!!!