I have the same situation, my account says it is closed/not bookable.
I cannot find any button to go live nor can I find any number to contact any agent or account manager from booking.com.
Last week there was a note on the extranet saying that they needed to gather some info and would contact me to make the listing live but I haven't had any contact from booking.com and the listing is still closed/not bookable
Also at the same time since yesterday seems that I have a one-night booking which could be an example,?.
It is not clear, there is a phone number but it is not live and the email address is not recognisable.