Life is all about Karma. It always gives you back what you give to others. No need for revenge. Those who hurt you, will eventually screw themselves up. And if you are lucky, God will let you watch. Keep faith.
I know a lot of people think of karma as a circle, but I think of it as more of a Mobius band or figure eight. What you put out doesn't immediately come back to you (like in a circle), but instead goes out and then comes back around (in my humble opinion).