Poor service

I received a call fron the agent of this company three and a half months ago, to sell a product which is more advanced than what I have with DSTV multichoice. The product is costing me R269 per month. Unfortunately I have not been able to access any channel on my TV, except channel 100. When you call them using the number on their website, no one picks up. I sent three emails to Denver Small (ref ***) requesting them to assist me or come to collect their decoder, but they give me the steps I need to follow in order to access the other channels. When I request their contact number he said the only way to communicate with them is through emails. I have already paid R807, but no service.