A company outgrowing itself is no excuse to not accurately follow a packing slip order correctly. It is the most elementary of tasks for a distributor. I had other friends on this very forum order around the same time as me and they had perfect orders with many many more useful spare parts than I received. So it's not a time thing, it's a hit and miss thing.
I hope that they do improve and cases such as mine and the OP are never heard again.
Like I said im not making excuses but ive seen it many times. Companies just grow faster then they can cope with because they make a good product and unfortunately it ends up hurting them.