Appalling quality of product

Please help My mother bought a Samsung fridge at Makro Amanzimtoti in July last year. The problem now is that the fridge is no longer working. It is still under warranty but we are getting nowhere in getting the matter resolved. Makro pushed us to communicating with Samsung directly as if we bought the fridge directly from Samsung. Samsung has however sent technicians to fix the fridge but it's been more than a month and still the fridge is not working. It's a frost free fridge but builds up frost to a point where the fridge part froze food and the freezer couldn't open due to the amount of frost build up. Technicians have been sent and their diagnostic finally concluded to an exchange to the unit. Samsung is however delaying the process telling us we do t qualify for an exchange but repairs. After how many repairs should the fridge get since it has already been fixed more than four times already. My biggest problem though is, since we were sent directly to Samsung to relay our complaint, what is the returns department at Makro for? Are they not the ones who should tend to this return and then they they deal with Samsung since they dealt with Samsung when they got to sell their products in their store? I'm very disappointed and angered at the fact that we as customers have to now do the jobs of people who are getting paid for whereas when the product was bought, they were more than happy to take the money from us with no questions. I really wish to come to a resolution with this matter and for my mother to hlget her money's worth as well as peace of mind. This thing has gone on for too long, it's taking a toll on her wellbeing. Please assist