Apple India — Display error

Address: Dharwad, Karnataka, 580008

Its been 8 months since i purchased apple iphone 5s and since past three months a black spot has appeared on the side of the screen and the display has become unclear. The touch screen doesnt respond many times. When taken to service centre (F1 info solutions and services pvt ltd, hubli, karnataka), they claim for an internal breakage or damage of the screen and say it wont be covered under warranty and seek a charge of inr 11, 000 for the replacement of the screen. Kindly help me out at the earliest