I just recently saw this; and, it's regrettable concerning your experience. One point of advice that I've 'tried' to inform builders not to do -which is NEVER place large or bold letters on large packages with the word "Fragile" or "Handle With Care". Workers (regardless of company/shipping) take offence to that and will toss or mishandle the package. I've been shipping ship models all over the world for 40 years and only had two bad experiences after removing those words from my packages.
Prior to that, only a few models were damaged because of my experimenting with packaging.
During the those 40 years, I found an inexpensive way of shipping where neither display case or model was damaged. It took a bit of engineering; however, I enjoy the fact that reinforced foamcore board cut shipping costs by 60% percent. Much of the shipping is based on weight. Foamcore is light (and most ship models are light as well). The most recent model I shipped (HMS Prince w/display case) cost a little over $100 as a Two-Day Priority package. It arrived to my client completely intact -as have my other models to recent clients.
Your model was a nice model; and it's good you received another opportunity to bring it to another level.