Short answer: Facebook changed its rules.
Details: Due to recent API changes, Facebook decided only to allow this feature when you have more than 2000 page likes.
Best solution to be able to get online bookings directly from your (<2k liked) Facebook page, is to convince Facebook they should lift this limitation: Ask them.
Within current rules, the only solution is to get 2000 likes. Real likes or bought ones (latter not advised).
A powerful manual workaround is just posting content with prepared booking scripts from the getBIZZI widget service. There is always a way getting your services noticed!
We apologize for this inconvenience but this is something we do not have control over.
For those of you who do have an active and widely appreciated Facebook page, make sure your followers are even more charmed by your integrated online booking service. Clicking a ‘Book Now’ button and claim your appointment within Facebook maybe more to their liking!