I recently read that it only takes like 2 or 3 people reporting a picture, post, etc. on Facebook before they delete it and they often don't review it before giving it the axe.
Try posting it without that link so that Facebook doesn't block it and see what happens. Perhaps you should make the page private if it's not already? If that doesn't work, filing some sort of complaint with Facebook is probably all you can do and I'm not sure how effective that will be. The way their reporting system is set up it only takes a few people (or even just one with multiple accounts) to consistently get your shit taken down if they are persistent.
Try posting it without that link so that Facebook doesn't block it and see what happens. Perhaps you should make the page private if it's not already? If that doesn't work, filing some sort of complaint with Facebook is probably all you can do and I'm not sure how effective that will be. The way their reporting system is set up it only takes a few people (or even just one with multiple accounts) to consistently get your shit taken down if they are persistent.