All facebook likes that were added, disappeared within a day

I have been generally happy with the SEO service, however I receive regular drop off's.

I spend a lot of $$ on whitehat SEO (Facebook advertising), and their drop off rates are no better than any other method, you just end up paying more $$.
I like to maintain a high reach, through up to 20 posts (organic content) per day, this gives people more opportunity to dislike a site, though as a downside.

However this all being said, my last experience of 1000 quality facebook likes, was very bad. While I was asleep (5 hours, approx 650 of the 1000 likes had disappeared).

It's possible this was actioned by facebook themselves, but normally if they are actioning it, my post reach drops dramatically as well, but that had continued to go up.

Not happy!