Lenovo — Crack on phone display

Address:	226003
Website:	Flipkart

I purchased lenovo k6 power through Flipkart on 24 april 2017 in mumbai and due to some reasons and shifting of my location I checked the phone later and I saw that The phone display have damaged and Flipkart refuse to replace the phone he told 18 day's have gone but they mentioned in "Flipkart replace policy that replace can be done within 45 days" how to resolve my problem or how can I take a legal action against Flipkart .. and may be Lenovo is making low quality phone ... How will resolve my problem