Thanks for all the great responses about whether to refund that
deposit to the original debit card (with his fiancee's name) or by
business check directly to the customer (the guy) I dealt with...
The thing that tipped the scales was advise from SCORE (Senior Corps
of Retired Entrepreners). I'd forgotten about this resource and it's
worth mentioning again. (Thanks Pam for the tip!) Whether you want
specific advise for your state (as I did) or not, you can contact up
to 5 counselors - I heard back from all three I wrote to within 2
days - and it's at no charge. They cover all sorts of issues
entrepreneurs have to deal with. The address is, oddly enough
www.score.org. Oh yeah, the advise was to refund to the original
card. I hope they'll be able to settle it out themselves fairly.