Fictionwise really got screwed in the Agency5 price-fixing fiasco in April, and B&N is not supporting them. I have books on my bookshelf that I can't download either, but because I followed the Agency5 issue here and elsewhere online, I knew ahead of time. I only "lost" one book.
However, that doesn't explain your microbalance "disappearing". Fictionwise has always dealt above-board with its customers, even though sometimes its communications are...lacking. I'd suggest trying again with the email address:
support@fictionwise.com if the web-based contact form isn't working for you. I've also received emails from
info@fictionwise.com. You could try either of those.