OnAir is a ****, dont buy from them

Got a call few weeks ago from OnAir and was sold a dstv stream, the sales person was talking so fast i misheard alot, suppose to pay R99 for 24 months, thought maybe i get a subscription of dstv or netflix or showmax, after unboxing, i realized that i get nothing, the dstv stream cost R599 in most retail stores, i called within 7 days to return the thingy. I was told i have to pay R400 cause i opened it, if i didnt open it, it was gonna be R200, since when do we pay to return a product? This is a ****, if anyone can assist, please assist and clarify on when did CPA amend the rule that we pay for returns, I'm so disappointed right now and they busy calling me