Purchased IPhone 6plus on 8th May and I switched ON my new phone for the first time to setup my account and I saw some grey mark in the display.

Purchased an IPhone 6plus on 8th May from Apple store, Bridgeport Village. Now I am in India on an assignment. When I switched ON my new phone for the first time to setup my account, I saw some grey mark in the display.Immediately I visited applecare,India. He said the display is liquid damaged, where as all other parts are intact. Infact water damage indicator is still showing white color. How to proceed now? what is the solution?