contacting booking.com as a host

How do i contact booking.com as a host?

If i call the helpline it asks for reservation details which i don't have as i'm a host

I've the following issues:

1) when i log in sometimes the property i've registered is there, sometimes its not, even though its the same login details

2) its asking for me to use a channel manager but i hoped to avoid this as i had the calander links from air bnb

thanks