Time to get spiritual. For some reason, your comment made me think of an interesting conversation I had while I was on a walk once with a friend of mine who is a Chan Buddhist monk. We were walking by a hotel in Boulder, CO called the St. Julian. I had always hated that place since it was one of the first large development projects that came in and started to change the feeling of the downtown area. That and they had rejected me as a job applicant.
I related all this to him and mentioned that I liked to "get back" at them by regularly walking in and using the lobby bathroom. He looked over at me with a severe expression and said, "You may as well have been pissing in their mouths."
I suppose that's the point in the parable where I was "enlightened." My friend's meaning was that, by acting spitefully and vengefully, I wasn't doing myself or anyone else any favors. I think the same could be said of OP's story.