#Amazon contacted me again. If my son sends the receipt for the cost of shipping the wrong server back, they'll add that to my refund. That will still only be about $210 out of the approximately $350 that we've spent on this.
I'm still not happy with them and especially not with their marketplace vendor (who claimed that we damaged the Citrix server and therefore were not entitled to a refund). I'd love to send them the photos of the packaging and the server itself (including something hanging off the back, a corner taped shut with gaffers tape, both of which look like pre-shipping damage).