Faulty Samsung Home theater system

This is the second appliance I bought from Makro Silverlakes. The first was a LG system which was replaced after months of fighting with a Samsung system. The Samsung went back twice now for repair but are still not rectified. I am insisting that Makro replace it with a new one. I do not care what the supplier say, Makro is responsable as they are the one selling this poor products to the public.