This hasn't happened to us but it did happen, twice, to our Superhost friends in The Algarve of Portugal this past summer. Surprisingly, it was also with groups of young girls, not boys as you might imagine. I know that one group came from Austria, but I'm not sure about the other one. In both cases, our friends had received continual complaints from the neighbours about noise and partying at all hours, which made them look bad (and is, I'm guessing, one of the reasons there is so much backlash against Airbnb hosting these days).
In the case of the Austrian girls, they not only made a mess of our friends' house, but also of the entire area. In one nearby bar, they apparently broke some ceiling lights being drunk and crazy. In a restaurant not far away, they took off their clothes and went swimming naked in the fountain. I'm not sure what came of this in the end, but I did hear that the police were called.
Our friends were in a serious dilemma. There was damage to their house (stains on the furniture, towels ruined by what they thought was MENSTRUAL BLOOD, trash can broken, glasses broken, etc.) as well as to their reputation with their neighbours. However, they knew if they wrote a review about either of these sets of guests, then the guest would easily figure out that the review was probably a bad one and retaliate with a bad review of their own. Then they would lose their Superhost status.
Instead, they contacted Airbnb and sent photographic evidence of the damage. But the last I heard, this had produced no results for them. They said that Airbnb was "indifferent" to their complaint and that it didn't look like anything would happen.
So, I don't really know what to tell you. This seems to be one of the weaknesses with this platform, and until the site takes the hosts' perspective into more consideration, then it seems like we're all going to be playing "Russian roulette" (sorry, bad pun) with our bookings.
Good luck in resolving this. Hopefully one or more of our fellow hosts has a solution that I wasn't able to offer.