Develop some equanimity around the fact that injustice is universal, and then see what you can do most effectively in response to this particular instance of it.
"Human history is filled with people doing disagreeable things. So drop the perception that you or your loved ones are being especially victimized. Mistreatment is a common thing, and anger is not going to help you deal with it effectively. You’ve got to clear your head if you want your response to injustice to have a good effect. So try to develop some equanimity around the fact that injustice is universal, and then see what you can do most effectively in response to this particular instance of it." ~ Thanissaro Bhikkhu "With Each & Every Breath: A Guide to Meditation"