It happened to me also. My pop-question "Can house-elves use wands" also got deleted from the site.
There is a link 'report' for every stuff (image, video, pick, quiz etc.) on this site. If other fans find your posts offending, inappropiate, wrong or factually-incorrect, then they can report it to administrators (maybe) and the review it and take descion. Maybe other fans have reported it to them and they have deleted it.
Unfortunately, there is no way you can get it back (If there is, I don't know). :(
