That's so horrible!! I'm new at buying hatching eggs (this is my first year) but even I, a newbie, understand the risks that come with shipping eggs. The seller is ALWAYS careful because it is always turned into their responsibility when something bad happens. They are also the best people in the world when things go right! A lot rests on the sellers' shoulders so they can't afford to mess with an order when packaging it for shipping.
I have ordered hatching eggs from a very reputable seller. She shows pictures of all of her hatches and periodically checks fertility and always checks in with buyers on how things are going. She takes it very personally when the PO messes up packages because it ruins the egg's viability and fertility, which then lessens the hatching rate. This happened to me. I didn't think of distance and the PO ruined the air cells on my first order. She then offered me a second order and only asked me to pay for shipping. The PO left it in a their office for over a week. Guess what happened when I tried to incubate them? Nothing. She felt so horrible, she sent me a THIRD order at no expense to me. I got a hatch from it.
But it just goes to show that she is a good seller and it sounds like you are, too. You offered to work with her if only she would cooperate. She wouldn't. I think she was trying to scam you from the very beginning. If she knew the risks, she shouldn't have bid on them.
I never hold it against the seller when something happens after the package has left their hands. They can't control the PO or the weather or anything but themselves. From what I'm understanding, you're a very fair seller and I'd work with you any day!!