Do you have it in your house rules that guests will incur a $250 fine if they don't put the trash out in line with your check in, instructions. Do you remind guests before they check out of the importance of doing so and fines for non compliance? @Jason843
I do hope you left an honest review for these guests to warn other hosts considering letting them book and a maximum three star so they can't IB. (I couldn't see anything but very positive reviews for your last ten guests !!)
I know Airbnb does cover additional cleaning and staining to furniture etc as I have friends who have successfully claimed for smoke damage and damage to sofa's and bed, so they definitely cover additional cleaning not just items which are broken. So perhaps you can appeal?
Guest damage is very rare - I have been hosting for nearly five years, had hundreds of guests and never had to make a claim. I think we can keep up good standards by factoring the cost of wear and tear into our day rate and careful vetting of guests to minimise the risk of problem guests.