@Clare97
1. If you look at the CONTACT AIRBNB post (currently a couple of posts before yours) it shows you all the ways to contact Airbnb.
2. I don't really know what you mean by 'Airbnb didn't recognise my acceptance of a guest'. If you don't have a confirmed booking showing in your calendar and you haven't received a booking confirmation then the guest hasn't booked and paid and if you accept him to stay with you, you will not be paid.
Not quite sure how you have been in contact without a confirmed booking. The only thing I can think of is that Airbnb accepted the booking, you got a confirmation then there was a problem with the payment and they withdrew the booking.
Call them now.