N11 Sent Me a Laptop With a Broken Screen - Refused to Take Responsibility

I purchased a laptop, which was stated to be under warranty, from the seller "Koyuncu İletişim" through the N11 platform with order number 206418454737. The product was delivered to me with a broken screen. When I returned it, the seller refused to take responsibility and demanded that a report be filed with the shipping company. The product was sent back to me in an even more damaged condition. Throughout this entire process, neither the seller nor the platform accepted responsibility, and my grievance has not been resolved. I kindly request that the necessary steps be taken to protect my rights and compensate for my loss.