Usually I don't use Chinese sellers except for low value bits and pieces but when I did I ended up with a bad copy of MP-27. The bumper is totally missing and one of the wheel mounts is damaged and floppy. It looks like it isn't even the correct pin. Unfortunately I only just got round to opening the box over a month since it arrived so it's out of the normal returns period. What are my options if the seller doesn't accept the return?