A coworker who was the reason why I was moved to another department (she is friends with the manager) changed departments herself and now I sometimes have to work with her.
First time she saw me at her new position she greeted me as nothing happened, as she wasn’t the reason why I was moved laterally. I replied with a non effusive hi.
I don’t engage in non job related conversations with her, if I have to work with her I just ask her in a neutral voice where is what I need and proceed to do my job. Otherwise I avoid her because I don’t trust her. I don't have to work with her whole shifts or every day, which is good.
The incident I mentioned on my first paragraph happened 2 years ago and I still remember it enough not to like that person. I don’t know if more mature folks would have already forgotten about it but I cannot. Am I holding an unhealthy grudge? I mean I’m happy if I don’t have to see her.
Even if you are completely correct and this person conspired against you; holding onto this is not great for your mental health.
The best thing for you is to acknowledge that you were hurt by this and accept that. Then move on, what they did was about them and not you.
From your text, it could be that they were just selfish and you were collateral damage. My advice stands, give yourself the freedom to move on.