What is the point of a warranty?

I bought an expensive LG TV from Makro in June 2016. When I unboxed it at home, it had no sound so Makro switched the unit for a demo used one that was working properly. Since this incident, it has had to be repaired another 2 times for various problems. Now it has broken AGAIN so I requested it be replaced with a competitor brand on 28/11. I was promised that this would be reviewed on 6/12. I called to follow up after hearing nothing on 19/12 and was told by Pulisani that they were "too busy" to look at my claim. I am now furious as I have had a broken TV for over a month and Makro is "too busy" to assist me. What is the point of having a warranty if the customer is ignored? If this cannot be resolved quickly, I will be escalating this complaint to the Provincial Consumer Affairs Office.