No support or feedback for complaint

In October I signed up for DStv. It hasn't worked properly since. I have had the first installation people over 5 times, and the second installation person has been round three times. I continue to get an error message saying bad installation. I have replaced the decoder in case it was a fault, redone the wiring, and had the dish checked. All at my expense. Whenever I call the call centre their only suggestion is to reset the decoder which makes no difference. I am paying my subscription and only get a few channels. I have asked three times for the call centre to escalate the problem but never have any follow up. I need multichoice to respond because I can't think of anything else to resolve this!