That's not how import/export works. Everlast doesn't do business in Panama. They were sold to Pricesmart (a US company) in the US, probably FOB San Francisco. From there it was up to Pricesmart to get them to where ever they were going to sell them and deal with shipping, customs, etc. The blame is not on you, it is more likely on the shipping carrier which was hired by Pricesmart, so your issue should have been handled by them, and in fact it was. That is exactly how it is supposed to work. If you have seen the factory videos, all Everlast machines are tested at the factory, in fact many customers bitch because their plasma torches have burn marks on them from that testing. There is a chance that the damage was during the China to US portion, and Everlast would be responsible for that, but since the machine wasn't run in the US, there is no way to tell. So the last carrier that touches it, is usually held liable.
Long arc, short arc, heliarc and in-the-dark!