Booking.com's Dysfunctionality!

Am a member of several accommodation sites - of which Booking.com clearly rates as the most inaccessible & dysfunctional, alas. . .

1) Any way in heaven or on earth to directly dialogue with B.com for direct account help, rather than spending one's life researching databases?

2)  Why, after importing/exporting Airbnb & Trip Advsior Calendars, is Booking.com the only accommodations site whose calendars fail to list ALL the booked dates of its companions, thus creating much needless havoc.

3) Why, when attempting to manually block out dates booked by other sites, (selecting start/finish dates & selecting 'closed" & 'save') do these dates continue to read '1 left to sell', as if they are still open to book?

Madness!

For any help here, my sincere thanks.

Joseph Marcello

Northfield, MA