Hello @NewOrleans0
I am truly sorry this happened to you, it sounds beyond dreadful.
I am not clear from your post when you say you have contacted Airbnb, did you do this through the Resolution Centre as they suggest. If not, here is a link https://www.airbnb.co.uk/resolutions
My other advice is to also put in a claim for on your home insurance, so they can work with Airbnb regarding your claim. There are areas that Airbnb don't cover, so hopefully your specialist home insurance for STRs will be able to cover some of these.
Please do leave an honest review to help protect future hosts. - 1 star across the board mention the damage and the people staying who hadn't booked, thumbs down. DO NOT mention your claim or this will be grounds for the review to be removed,.
One thing I was rather puzzled about in your post was , that you didn't seem to have CCTV or other camera system outside your property, or you would have spotted that many more guests were staying at your property than had booked.
I know you are a much more experienced host than I am, but this would have given you video evidence to help back up your claim as well as helping you evict these awful guests before they had a chance to stay and create such damage.
Too late for this time, I know , but something to consider going forward when you have recovered from this awful situation.
I do hope you are able to make a successful claim, do let us know how it goes if you can as it will be invaluable for other hosts to help understand Airbnb's guarantee process.