This seller got one correct way to do.
Wile,
I know that some seller do not offer to their buyer one minimum of support to solve problems like the lose of some spare parts.
This to solve some little problems that the normal watch use can get.
I think, it's normal to lose some screw or some little piece, on the wrist using ;
and some, ( IMO ) not correct seller, do not get this spare pieces nether if you pay it.
So, get all your considerations before to chose a seller.