Paying for something which i'm unable to watch and that is not my fault

Early this year DSTV offered me an explorer for free since i was a loyal customer, I didn't ask for it, it was given to me by dstv for free while during that time i was happy with my normal HD decoder. In July one of their accredited installers came to install the explorer, i regret the day that guy came to install it because now since that day i am unable to watch TV but i have been paying all this months. when i try to call the installer his phone is off and when i try to report him to dstv they also cant get hold of him. I have been calling for the past 2 to 3 weeks but till today i cant find any solution