@Amy2142 You may request money from the guest via http://airbnb.com/resolutions . If the guest agrees to the charge, it will go through right away. But if they refuse it, a lengthy drama begins wherein you have to escalate the damage claim to a mediator who will assess the evidence you provide and determine whether to compensate you. Meanwhile, the guest still has the opportunity to retaliate against the charge in their review, and you can't really do anything about that.
As I'm sure you realize by now, Airbnb doesn't have your back - that's just marketing. They deliver bookings and process payments, but other than that you're on your own.