I suppose, you occasionally deleted application which calculates your actions. I've got the same problem, and today I couldn't earn any credit from Twitter account. Yesterday I was cleaning my applications in Twitter account, and to sorry, didn't know which one belongs to this website. It would be good if the application had some description reffered to this website in order not to delete it again.
And a period no longer get credits.You must "follow" as many new pages as you gave "unfollow".If you "unfollow" 10 pages for example you must "follow" 10 new pages without you get credits.After that you start to get credits again.