Sorry, this isnt exactly offering help, but this outfit (in LA) was one I was looking at myself to go and do some flying with. Their airfield (Brackett) is quite close to a friend of mine. I'd be grateful if (when you've been and returned) you could give me an opinion of them.
In this particular case, have you phoned/emailed them yet & asked for advice/help/co-operation on what to do?
I'm assuming you've probably booked a cheap-no-refunds flight out there which means you are committed to going on Monday whatever. But if not, how about negotiating a delay before you go? May be worth paying the airline some extra to make this possible?