Customer service contact

I received a bookibgvfrom booking. Com and airbnb for the same dates. Because the airbnb booking waz before the bdc booking. I havecasked the guest to cancel or change their dates.

I have messaged the guest twice now but not receiving any reply. The booking is in 1 month time. Can i cancel the booking myself as the host? 

Lucky Tuna

How it might happens ? Did you sync your calendars  between Booking & Airbnb ?