Shocking service

We purchased a Sinotec smart tv 4 years ago at the N1 City branch, bear in mind the warranty is 5 years. Since May this year, the power goes on but there is no display on the tv. We took the tv in for repairs 9th June and it came back 1July, only for us to get home and discover that it still had the same problem that we sent it in for. I called the branch the next morning (2 July) and spoke to Dominique who said that she is logging a ticket for the tv to be collected at our home. A week later, after no communication whatsoever, I called again and she said it was logged and they will come out (no apology or trying to follow up) I then decided to call the Head office and they logged a complaint because nothing was logged and they had no record of our complaint.They then finally came to collect the tv on the same day 9 July. In this week of the tv standing once again, the tv went showed display once and my husband played a 4K movie but it said "unsupported file" but according to our purchase and the box the tv came in (we have proof) the model that we were under the impression we bought, as per the box, is STL-50E6000M 50" UHD smart LED tv which is a 4K tv but when my husband checked the model number of our actual tv we have it was model stl-43e390 smart tv (rtd298x_tv001) which is in fact not a 4k tv. I am so Fed-up of this being without a tv for months on end and the tv being "fixed" just for it to have the same problem after waiting so long for it to be repaired and Hi-Fi Corp to giving us the run-around, not following up and having to call and request decent service from you people!! I dont want that tv any longer because I didnt purchase a tv for it to last a few years and I definitely didnt purchase the tv I was given in the box. My whole family have been buying from Hi-fi since I was very young but I can promise you, I wont buy from this company ever again and that goes for my family and friends too. And we were just going to buy a microwave last week but from the service we received we bought it at a different appliance store yesterday. You have lost a lifetime customer