This topic is one which most people (including myself) find most difficult to follow. It goes deeper than forgiveness. And as hard as pardoning others can be, what I am suggesting is to forget everything that someone else has done or is doing to you (while remaining safe at all times) and return to them heartfelt, warm feelings of understanding.
Now, I know this will send. Some people into an argumentative state. Let me say, I understand and forgive that. Returning kindness for evil goes against the grain of justice and all impressions of right and wrong. Do not misunderstand me, for anyone who breaks the law I believe jail time is in order. For your own peace of mind, there is no need to imprison yourself in the vortex of hate.
Sometimes, holding on to the anger serves us. As it is probably what got us through the experience in the first place. Once ended, let it go. The person executing the unprincipled behaviour will be in a hell of their own making. That is a formidable fact to deal with. Mind you, they may blame others and make excuses. That it itself is a whole other prison. By holding on to any bad feelings you are also participating in the revolving door of malice.
Find a way to step back from the emotions of the situation and regard these people as lost souls. Hurt people, hurt people and you must see them as tortured individuals. Normal human beings do not want to wound or harm another. Unintentionally or not.
There is a higher road available. It may require a good deal of inner work to get to the point where you cease to feel resentment towards the antagonist. It is well worth your time to put in that toil.