@Ella4855 Airbnb generally doesn't advance Resolutions claims for anything other than physical damage. They don't enforce host-issued fines, or accept liability for third-party fines such as those from building management. It's sloppy of them not to respond to your messages, but that case is DOA.
Charging a refundable fee upfront would be a workable alternative, but this works best if you're physically there for the checkout. Guests will have a more comfortable departure if they know that outstanding deposits have been resolved; if they feel surprised by a charge later on, they'll punish you for it in the reviews.