Oh you poor thing, does make you so cross though. One our daughters and her partner recently bought a flat pack conservatory and when it was delivered and they had checked it over a door and the guttering was missing!!!! As you say nothing small.
Brilliant idea on your part though with the skateboard, that saved some stress and injury.
Hope you soon get the part you need - they will probably pinch it out of someone elses pack:)

Lynn xx