Lost faith in a supposed global brand

I have reported a terminal issue with my new TV on 14 September and again on 17 September. Both times via a chat function online, and ran through drawn out troubleshooting issues when I clearly stated that the unit was powering up and then down again within 30 seconds. I had to insist with a repair request being logged. Without any update or communication, I again contacted Samsung to follow up on the progress of the request. They had not yet referred it so a service partner. Following a third attempt, I was then contacted by the service centre requesting that someone be at my home for the next day for a technician to visit. This never happened and no one contacted me. I then contacted Samsung by phone (as I now had a number to call from my received call) and voiced my dissatisfaction with the customer service agent demanding that a decision maker contact me to resolve this long outstanding issue. No resolution, other than more waiting time for me. A day later the service technician visited my home to assess the TV fault. He confirmed that the motherboard was faulty. That was 10 days ago. Samsung has since declined the replacement of my TV, but following me pointing out the correct transaction date, submitted the request for approval again. on Thursday the 3rd of October I was contacted to confirm that the claim was approved. Today I was contacted again to confirm this, again! Now I need to wait for the courier to contact me about a date and time for the swap out.

At what point do you own the process of managing a customer issue? This is the second time I have returned a TV on this order. I'm really not impressed and will think long and hard before purchasing a Samsung product again.