I'm sorry you had such a hard time Susie. This is a tip for you and anyone else who joins this kind of swap. It would have helped if you had used all baggies instead of tightly sealed envelopes to contain each person's seeds. I was able to tell in seconds if a baggie had the right number of packets in it, which is really all I looked for. A few times I opened the baggie to count packs by hand, which I only did if the number on the packing slip was folded over and I could not see it otherwise or the packs were hard to count for some reason. Most of the time I was able to push packets around in the baggie and count them without ever opening the baggie. Aside from a couple you had in baggies, your white envelopes were so well sealed that they would have been destroyed by trying to get into them to count so I went by the packing label. If I had torn them open I might have caught some of the errors. I should have done that. That's a lesson for the host.
I received a pack from you that is not what it is labeled to be. You got it in trade so you may not have realized it, or you may have put it in the wrong packet. Counting packs would not have detected it. I've made that mistake.
I help myself avoid mistakes by preparing packs as I have time in early fall to get ready for swaps. I do that for a number of reasons, but it does help me keep myself straight on what I have and how much of it there is and I don't get overwhelmed as I add seeds to my swap cache as swap season develops. It does not keep me 100% mistake free, but it helps. Others may have other tips.