Apple India — Lines on iphone 5s screen

Address: New Delhi, Delhi, 110062

Website: apple.com/in

I bought this iphone 5s this march. Today when i woke up this morning my phone was fine but after sometime i saw these lines on my phone's screen. I put my phone on charge, the screen came but with lines on it. I went to service center, after waiting there for good 30 minutes they told me that the screen is gone due to some pressure on it. I told them that it not possible coz it was working fine till morning and as soon as i saw the problem i came to service center and while he was checking my phone the display came back in front of that guy, but instead giving me some solution the guy started telling me that it will cost rs12k for screen replacement. Its just a 3 months old handset with proper warranty. I need my phone to be repaired or replaced as it is under warranty. I hope apple will do justice