I think you can try to appeal this. When you call you should ask for a
supervisor because of the complications of the case. Never call on the
weekend or non usa work hours. I am sorry this happened to you. I do not
sell expensive things here anymore ...
I have had people check out my listings in person. When I had vintage
guitars, they wanted to try them out. I never had a problem. Since your
item is very expensive, meet the buyer in a public place (police station
is the best) and bring a friend.
After all the police reports are filed, including one local, you may be
able to file an insurance claim. Whenever and however we have sold a car
we keep it insured for a little while.