Alexandra, I feel your pain. Most of what you say is common to us as well. We think we lost about $2000 through this underhanded, covert tactic by Airbnb, and they couldnt care less - let alone even consider compensation. It took us about 3-4 weeks to have it rectified and we had to stay on their backs every couple of days. Their care factor about your loss of income is zero. What we did whilst we were waiting was we added a statement at the start of our listing to say that we were an instant book property, and that if instant book wasnt working we would get back to you immediately. Not sure if it helped (our income suggests that it was marginal help at best) but we felt we had to do something - Airbnb werent going to help any faster that Fiji time.
The other tip - they wont get back to you when its rectified (remember care factor is zero) so keep checking your searches before you call them to demand where they are at.
We are currently reviewing our position with Airbnb - too much stress created by them - how can you sustain a business when your prime supplier so obviously and blatently doesnt have your back (and is argueably working against you)
Good luck