Paying for service you not getting

I've been calling Dstv with the same problem the whole time, I'm paying my subscription every month for nothing, I call their agents and they just want error codes, I inform the there is no error codes just a black screen that shows, you can watch a Chanel now to later get a black even on normal 192 or 194, then the other channels will show, so what is wrong here, you pay for service you not getting.