Grundig 65 GHQ 9500 Had Screen Darkening and They Refused to Replace It

The Grundig 65 GHQ 9500 model TV I purchased four days ago was delivered to me. The service team came and mounted it on the wall. We asked them to test the TV, but they said they never encountered any issues with this model and left without running a test. Later that evening, while watching TV, we noticed a darkened area stretching across the right side, especially in the lower right corner. We performed a white screen test ourselves and saw that the darkening was quite severe. We immediately reported the issue, and they said a technical service team would be sent. When the technicians arrived, they confirmed that there was indeed an abnormality and called their supervisor. However, the supervisor, who was not even present and had never seen the TV, claimed that the dark spots were normal. The technicians then ended the call and left, saying this was to be expected. After they left, I gave negative feedback in the satisfaction survey. The next day, Arçelik contacted me and said they had opened a request for a replacement and would send another service team. However, as soon as I ended that call, Grundig called me again, saying the issue had already been reported as normal, the factory was informed, and they also deemed it normal, so my service appointment was canceled. I have completely lost confidence in this TV, which I paid ₺35,000 to ₺40,000 for, and it has only been four days since I bought it. The primary expectation from a TV is good picture quality, and despite experiencing a serious issue, the company refused to stand behind their product. No one should buy from this brand or recommend it to anyone. Only we know the frustration we have endured for the past four days. We paid a high price only to be left with a faulty product and poor service. Neither the service, the supervisor, nor the product itself has been satisfactory. In our opinion, both the service and the product are terrible.