My Samsung A15 Phone Developed Issues Within 8 Days, and Service Denies Repairs

I purchased a Samsung A15 smartphone from Vatan Bilgisayar, and it developed issues within just 8 days. Both the Vatan Bilgisayar and Samsung representatives acknowledged that the screen was burned and advised sending the device to the service center for a report. There are visible spots on the lower left side of the screen, and the touch functionality is not working. The issue was confirmed using Samsung's own app. I sent photos with evidence to Samsung customer service and BDH. BDH sent the device back, claiming there was no fault, even though the issue was clearly present. When I contacted BDH, they stated, "We, as BDH, do not handle replacements. If Samsung approves, they should replace it. We don't care, go ahead and apply to the Consumer Arbitration Committee." When I explained the situation to Samsung customer service, they responded, "What the service says is what matters to us, not what the customer says," and hung up the phone. Samsung claims BDH is their authorized service center, but BDH refuses to acknowledge the problem. I feel completely disregarded by Samsung, a global brand, which seems indifferent to customer dissatisfaction. They suggested sending the device back again if the problem persists, which feels like they are mocking me. I was torn between Apple and Samsung, and now I regret not choosing Apple. I will never buy Samsung again.