What this person did to you might have been wrong, but (as the old saying goes) two wrongs don't make a right, and it would be just as wrong for you to strike back at them in anger and revenge.
Why is this? One reason - as history repeatedly shows - is because this easily turns into an endless cycle of revenge and hatred and violence. Someone hurts you; you hurt them in return - and then they strike back at you, and the cycle continues. What is gained by that? The answer is - nothing. In fact, it only leads to continued insecurity and fear and anger.
But the Bible shows us another way - the way of forgiveness and reconciliation and peace. The Bible says, "If your enemy is hungry, feed him; if he is thirsty, give him something to drink. In doing this, you will heap burning coals on his head" (Romans 12:20). In other words, by refusing to seek revenge, and treating someone in a way that is opposite to the way they treated us, the cycle can be broken, and peace can begin.
This, after all, is the way God treats us. By our sin and neglect we have hurt Him far more than anyone has hurt us. But He still loves us; He loves us so much that He sent His only Son into the world to die for us. Open your heart to Christ, and then ask God to help you love others - even those who have hurt you.