Lol get over it. She improved her test grade on exam 2 so he probably dropped her 1st exam and kept her grade on the final. You did not improve, so your grade wasn’t dropped.
Don’t concern yourself with the grades of other people. Technically, students aren’t even supposed to discuss it I don’t think (FERPA stuff). I’d bet you $1 million going to the Dean won’t do anything besides make you come across as entitled.
Get over it.