That really sucks. I'm really sorry they put this together so badly. I'm not sure I've seen Games Workshop have deals that frustrating.
Ever since Nike did their limited editions, it's you have to be careful when buying stuff. They package things for collectors, scalpers, and whales and make the average customer buy it on eBay. You know how Stanley drink cups have been super in style? Guess where the limited edition guy from Nike went when he left Nike.
It's really awful. It's maximized wealth extraction, leveraged with FOMO. It allows the producer to make something that exploits the customer and relies on the existence of a robust secondary market backed by the Internet to function at a very basic level.
WotC has been pretty bad with it. WotC has Secret Lairs and the 30th Magic Anniversary set. Even arguably the D&D FLGS covers qualify, but at least those are kind of a good cause. From my memory WizKids has been bad with it, too, but I don't buy their products anymore so I don't know. I do remember the HeroClix MechWarrior was an absolute nightmare to get what you wanted, but when I played the communities were pretty small and nobody was buying solely for resale.