Unfair and deceptive guarantee return policy

I bought a Sinitec 49 inch UHD smart TV in 2016. Last year, TV would not switch on. I sent it to Makro Montague Gardens for assessment,TV was sent off for repairs. After a couple of weeks, the problem occurred again. When I returned to Makro, I was promised, by Yvonne at returns department, that if the TV broke again, I would get a refund. A couple of weeks after the tv was repaired, it broke again (so third time). When I returned to Makro and reminded them of the promise to refund if it broke for third time, they could not honor. Sent off for repairs. Now the TV is broken AGAIN! I am tired of being **** to PLEASE. This Is *********.