I'm currently dealing with the exact same thing right now. I sent a message to Airbnb and they called back. I asked them to put it in writing mainly because I was not able to understand the person that called me on top of me being partially deaf.
I have been dealing with this for weeks now and AirBNB says the only thing they can do is credit the renter back after. This hurts us as a host because I have to lower their nightly price to get it under their allowed amount including taxes. If they would take the taxes off ahead of time, I could leave their nightly price where it should be. Very frustrating as I am involved with tax exempt organizations and we NEVER pay taxes then have them credited back after.