Talk to them but in a civil manor, usually works better in the long run than ranting now. If something more serious than a piece of missing trim happens down the line a good relationship may be beneficial.
Trim pieces are probably a special order part compared to mechanical bits so may have to come from Japan, I know not good but get them to check. I had to wait a couple of weeks for Ford to get a suspension bolt from Germany. They change these things often and there are many variants depending on trim level , ie fogs or not, colour coding etc. so even if they look the same there may be subtle differences between yours (presumably a couple of years old being SH) and the current showroom model.
Mazda Northants were part of Autohous who were always OK with me on the VW side, although I noticed the day they their refurbished showroom now says VW Northampton, don’t know if it’s a change of hands or rebranding (as with Audi up at Sixfields)