How to prevent people from liking and commenting posts on your Facebook page if they don't like the page?

[Marouane]

I'm trying to do a competition in a Facebook page I created, in order to get more people to like the page, but unfortunately I see that people don't need to like the page in order to like or comment, plz tell me if there is a way I can stop this or at least get them to subscribe before they can comment or like !

[Hermione Lovegood]

You'll have to sort out your privacy settings but if it's the same people commenting you can ban them from the page, which might make life a bit easier.