These clowns are well-known on the board - numerous posts about their "business practices." It seems they read from the same script to everyone, since they gave me the same line of b.s. when I was selling my boat. "5 buyers looking for a boat just like yours, just send us $$$ and it will be sold."
These guys must cruise boattraderonline all day, because they called me out of the blue 2 days after my ad went up on boat trader. Sorry to hear you got taken, I'd contest it with the credit card company - VISA, Amex, etc can be real bastards about possible fraudulent charges (and charging for services not delivered sure sounds fraudulent - or at least unethical - to me).