Apple India — iphone 7 home button cracked

The touch id home button of my iphone 7 (Less than a year old, so still under warranty) cracked on its own and suddenly stopped working. The phone used to heat up a lot and the button stopped working one day when the phone was on charge. Tha apple care centres and the customer support team, both have been really unhelping and impolite in their sevices. They have denied any kind of service for the phone stating this as physical damage while there was no mishandling of the phone. The phone didn’t drop at all, so that couldn’t have caused the issue.