Unreliable installer

My dstv was installed by an accredited installer referred by multichoice around May 2015. Because of the place the dish had to be installed I was told to pay extra for a bracket. I then paid for the bracket and David from Mugodo digital installations did the installation. In September - just over 3 months after it was installed - there was a problem and I had to call multichoice. They told me to call the installer because the warranty is 6 months. When I called the installer he told me I have to pay R 350. I paid the R 350 even though I was told that there was a six month warranty. Its 2.5 months since the installer came and the dstv signal is gong again. I called him because its still within 3 months of the last call out. He has been promising to come for almost a week now. So i guess he will wait again until the 3 months period then i have to pay for him to come. I'm going to cancel this stupid dstv subscription - clearly the installers need to disbarred. How can one installer have to repeat a job 3 times - is it that difficult to install dstv with a bracket. I'm very angry