Find hidden contacts on groups?

[tbn1990]

I'm not sure how to really explain this, so I'll do the best I can. So I did the whole add group in order to sync contacts with Facebook thing. When i was going through and joining contacts together, I realized I was doing it wrong and deleted the Facebook contacts that I already added to the group. When I deleted it, it told me that it couldn't be deleted, but it would just be hidden. I know now how to do it the correct way, however, when I go to add the names into the group, the contacts that I "deleted" that should have been hidden, are no longer there. Does anyone know how to get these back? I've tried syncing my contacts and everything and they still don't show up.