If you want to get revenge, be successful. The best way to slap people who wanted to tear you apart is by showing them that you're winning. Success comes in different forms; it doesn't stop or is limited to the four corners of the classroom. It's for you to find out.
I once read that it's our human nature that tells us how vengeance makes us feel better, but it's only for a short period of time. Usually, if we're hurting, we also want to hurt them, depending on the level of pain it has been. Then there goes this saying, "If they throw you rocks, you should throw them bread," and personally, I think, why would I do that? If you can't treat me well, you should not expect anything in return. I'm a Scorpio, not a saint or an angel, if you'd ask me. But eventually, I realized there's too much hatred in the world, and I still have too much love to offer, if that makes sense. None from the former solved anything, but the latter has proved to be the most powerful thing on earth.
Besides, the more you take action, the more they can tell you're affected, boosting their ego for that kind of impact on you. And we don't want that; that's where we get abused. Showing them you're better off without them should be so loud that it won't make them feel they're bigger than oxygen, if you know what I mean. And you can start that by knowing your worth and acknowledging that you're someone's whole universe.
