DNSB, thanks for the response. Unfortunately, though there are several files in that folder, no epubs
I believe I'll put this in the lesson learned category, say "Screw it", and move on. I had B & N reverse the transaction and I'll buy the books from Amazon.
It's faster and easier to convert Amazon books to epub than to deal with this kind of poor customer service. Clearly B&N is making enough money not to need mine.