Apple India — Company denying to repair product under warranty free of cost.

Address: Kolkata, West Bengal, 700057

I bought an iphone 5s 16gb on 4th of March 2016. on 11th june 2016 the display pannel started featuring a white line passing diagonally from one end to other. i immediately took the phone to an apple authorised service centre. they kept the handset for about an week & then informed me that it is some kind of pressure damage which warranty doesnt covers. the only option they gave me is, I have to pay 19900 & then they will give an exact same handset.
now the physical condition of the handset is as good as new & neither it has ever fallen from my hand nor it has been mishandled. how does it automatically get pressure damage? it is a mfg dispute which they are not accepting. i bought this handset for Rs. 25000 & within 3 months they are again asking me to pay 20000 to get it replaced.

i want free replacement of my handset.