Nokia N97 Taken At Mobile Store Shop — Poor service from vendor

I have taken Nokia N97 phone from "Mobile Store" shop located at Virar (East), India. I took it to Norvey and then I faced one problem.
I have kept my phone for charging and suddenly I found my screen turned into rainbow colours.
Since it is under warranty, I have contacted to that shop "Mobile Store " over phone, but no proper follow up with Nokia Service Center.
Everytime I called from Norvey, they have reasons for not to give replacement/repair.

DO NOT BUY ANY PRODUCT FROM "MOBILE STORE" SHOP.