Charge for repairs without fixing the problem

Dion Wired in the Kollonade is the worst company to do business with!!! I bought a demo model Samsung entertainment system from them a while ago. When arriving at home, all parts were not there, even though the salesman ensured that it is a fully functional system and effectively brand new. When querying this, Dion Wired simply said that it is sold as-is, they can't help me with the missing parts. After sourcing this, just as the unit was out of warranty, it stopped working. It was taken back on the 3rd of December 2014 and was informed it should be sent for repairs. I was informed a quote will be given for repairs and there is a warranty on repairs, if the problem persist, the unit will be replaced. About 3 months later, after lots of calls and fights, we received a quote of R1,700, but they can't tell what needs to be fixed. Eventually we just agreed that it must be fixed. After receiving it back, the unit was still not working. We took it back immediately and demanded to speak to the store manager as the line staff are obviously not dealing with the issue properly. The store manager ensured me he will personally look into it. We received the unit back, still not working.