Iphone 13 screen suddenly started flickering and then turned completely black with two horizontal green lines without any user induced damage

My Iphone 13 screen suddenly started flickering and then turned completely black with two horizontal green lines at top. I've seen many other users faced this same issue across different Iphone models. The Apple Customer Care is asking a whooping INR 30,000-32,000 to replace the display after saying that it is hardware issue, which I think is very unreasonable, considering no user damage involved - there are "no" scratches on the screen - this all happened on its own. The display is black but I can still receive notification tones/vibrations. Can anybody please help? I even paid INR 2,000 to generate an official diagnostic report to send to the apple care team but they declined to replace the screen as a complimentary service. I feel helpless and frustrated as this is not my fault.