Last August (yes it's been bugging me this long) everyone in work got their annual pay rise. I got £500 which I was pleased about even though it's the minimum. Then I found out that my work mate who I supervise was given much more than me - almost double (she told me). I contacted HR asking how it was calculated, got told it was based upon performance. I decided to leave it but then HR contacted me asking if I wanted to persue it. I declined and they were quite keen for me to persue it anyway. I still left it but have continued to be annoyed that I as a supervisor, who is given more responsibility, didn't get an equal rise.
I have an appraisal coming up and wonder if I should mention it because I feel like it's unfair. I do earn more than her though.