I was treated like crap by my sorority, is there any way I can get justice?

I think that the best advice to give you is for you to get some therapy. The therapist can help you with this problem and advise you on how to heal yourself. With professional help, you can analyze what happened to you. It sounds to me like you got depressed first, and then your "sisters" did not know how to deal with you. They chose to torment you instead of reach out to you. Perhaps in your quest for trying to make yourself feel better and punish them for the way they treated you, you will find another option available to you. Perhaps the thing for you to do is write a very good letter to the advisor that wrote you the letter. There is a chain of command with these matters. You could write a letter to the person above the advisor. There should also have been a person in charge of the greek system on campus. You should have spoken with them. Most campuses have mental health counseling for free. I think you fell through the loopholes. You did not advocate for yourself, and they didn't advocate for you either. An organization is only as good or bad as it's current members. Those girls/young women are long gone. I would not hurt the organization. I would attempt to make it better through education of the people in charge at the school. I really hope you got your degree. I also hope that you end up being able to resolve your bitterness and anger towards this organization. Those girls were not nice to you and for whatever reason the advisor also did not support you. I think it's good that you are out of it. You could consider it a blessing at this point in time. It's healthier to look at it that way.