That has happened to us in the past on Ebay and we have always let them log a case with Ebay. We have always won the case, no matter what you do they are going to give you a negative feedback. Please share the buyer's ID so I can block them, i'll send a PM to the OP
The package of eggs actually arrived on Tuesday. A week for a package sent USPS isn't bad. Yes, it is longer than I would have liked, but not the end of the world when it comes to viability. That is the reason I only send eggs two days old or less on the day of shipping, so if it takes a while, they're still viable.
I'll send you a PM, Sands Poultry, I don't want to post it publicly.