Hyundai Motor India — Partial tray problem

Address:

At Vevoor, Near Gavdevi temple , Gavdevi road, Tal/Dist-Palghar. Maharashtra.

Recently i bought Hyundai Grand I10 Nios Cng at Sts Hyundai showroom Boisar Palghar Maharashta.
Rear sided partial tray not assembled properly. When i close rear door (5th door) presses it partial tray down side hence 5th door closes forcefully.
I complaint that problem to sale department and also to service department but no one intrested in solving my problem. Service department saying thats not our problem & Sale department saying that is not our problem.
I saw new same model at that showroom that car dont have that type problem. It means that is only my car's problem.
So do needful for rectify my genuin problem