A query from guest and communication with Booking.com

I have 2 concerns:

a) I need some help from Booking.com urgently and I do not know how to communicate with them directly. All my efforts end up in references to pre-published articles. And I am not sure if this present channel of communication is the best one. How do I get a Booking.com official to respond to my queries directly?  (Due to language issues I prefer not to phone in). 

b) I received a query from  a prospective guest who is experiencing technical problems to make a booking. I replied that I will follow up on the matter. Now I am in the position that I am unable to contact Booking.com directly and the system does not allow me to communicate anymore with the prospective guest. (The query was classified as a query regarding my property). Can anybody please help!!!!

Malan Heyns