Blocked contact should be show as blocked
If i block someone, right now, I cannot see he is if he is without clicking on it first, and see this is written "unblock".
I suggest to add some visual clues, like stricking the name of the contact, or something like this.
Moreever, I think Unblock icon should be different from the Block icon, because they are different action, leading to opposite result. I would propose to use a green icon, seems traffic light colors are quite universal ( http://en.wikipedia.org/wiki/Vienna_Convention_on_Road_Signs_and_Signals )