VERY BAD product and customer service

i have a Hisense 55 inch smart TV that keeps on freezing and resetting that i purchased from Makro Germiston last year in November 2017 , I log a service call , Makro sent out their technicians who then replaced the main board and redid the software but still it is not working properly.then Hisense sent out there own technicians to try and fix the problem but couldn't , I then sent then a video of the TV freezing and resetting as proof. i have had no response. When you call Hisense , the Mangers never answer there phones or you are told that they are in meeting and will get back to you but they dont. i have had it with Hisense and there customer service. i will never buy another product from them again if this is they way you get treated.