@Timo24 Hi,
I hope your exchange is on the booking page, since that is the record Airbnb looks into in case of disputes.
If not re-iterate their message through Airbnb - Hi Guest, this to confirm your Whatsapp message, just so I have everything on one platform for better oversight. You say ...... It's regretful that you were not interested in us checking you in, because we could then have shown you the typical features of a genuine old inner-city building with Monument status in the heart of the city.
If it's not on the message page yet, tell him: My cancellation status is X which is automatically agreed to and accepted upon booking. The apartment has been off the market for some time (if booked longer I'd mention the time), thus reducing the chances to re-book. However, if you cancel, then the remaining days will be freed up and I am happy to re-imburse you any and all days I manage to get booked.
By the way - never, ever cancel for a guest - the penalties are huge.
Stay unemotional, factual, and professional.
He cannot sue you, and if he does threaten you on the Airbnb page, you can report him via the little gray flag in the upper corner of the message. Airbnb do not react well to extortion.
Personally, I would be on the phone to Airbnb if it escalates quickly:
020 5222333 - it's a local # but switches through to the Ireland office, en ze hebben ook nederlands-pratende medewerkers daar.
Good luck.