MultiChoise charging for cervices not rendored

I will not recommend DSTV MultiChoice to anyone. I had issues with my decoder in the beginning of the year, so I asked to upgrade to the a new package with a new decoder. All this was done telephonically. The person that helped me gave me a date that their selected installer will bring the decoder and do the full installation. I had to take a day's leave from work just to sit and wait the whole Friday for noting. I phoned MultiChoise the Monday and after several attempts and a hour of waiting on the phone to find out what was the issue, they told me that they will escalate the matter and come back to me. I waited for a couple of days and had to go through the same procedure of phoning them, getting redirected to different people just to hear that they will again escalate the matter. Almost a month later I phoned them and told them to cancel my MultiChiose account and also the installation as I already paid for a months services that I could not use. I got reference no ***0I77 for the cancellation call. The end of the month came and they took money out of my account for the installation of the dish and decoder that I never received. I reversed the debit order and phoned them again to go through the same procedure just for someone to give me the accounts no for MultiCoice. Every time I tried to phone the no they gave me I got a response that the no does not exists and when I phone Muticoice they keep on telling me to phone account department with the same no that says it does not exist. Now The have handed me over to the attorneys for the installation charges and added interest on the amount. What can I do as I have cancelled the service and did not receive anything from them.