Longstanding client feeling **********!!!

I have been with Vodacom for probably more than ten years with spotless payment record, but my latest experiences with them have been enough to make me recosider. I have been **** to in the Northgate shop - blatantly plus they are still charging me Handset instalment fees - long after my contract has come to its end date. When to try to get hold of them on the phone or online, the numbers either dont work or you get sent around in circles. Only way to get their attention is probably to stop my payment!!!!!!!!!!!!!!!!!!!