Mike.. send your credit card company a notice that you are protesting the charge. You have so many days to do that after the charge is posted. Do it now. You can likely have the entire charge refunded to you if you're within the number of days allowed. I've done that myself. And, your credit card company can advise you as to the format of the complaint and the window for you to do it.
They're evidently in bankruptcy.. so I wouldn't trust their refund policy at this point. You could wind up as another creditor that doesn't have much standing. You know, pennies on the dollar if that. And, do read the contract you signed with them as well.
Hope you can find another venue up here for your business retreat. cheryl o7o