Grade Dispute Question

I checked my grades the other day to see where I was at and saw that I had a B in a class that I thought for sure I had an A in. I emailed the professor and asked her if I had forgotten anything, and if so, there was anything I could do to bring the grade up. She sent me a mean spirited email about how she was offended about how I said that I was taking the class as a gpa booster, which was taken totally out of context from something I said during the middle of the semester. Anyways, she sent my grade sheet and I had a 0 for an assignment which I did and I promptly sent her a photo of the assignment and the grade, which correctly added to my score would’ve given me a 95% A for the course. She sent me an email back and said she bumped my grade to a B+ and explained it by dropping points in another assignment which she felt she had been overly generous with. Do I have a case against this professor? It seems like she’s trying to get revenge on me from a comment I made in the middle of the semester by tinkering with my grades. Is she allowed to change assignment grade after she has submitted them to me because she feels that I did not do enough to earn an A although my point total warrants an A according to her syllabus?

I think it might be useful for you to set up a meeting with the chair of the department to share the emails you received and your concerns. Be sure you bring evidence of the emails, your grade sheet, and the revised grades, and focus on the facts, not your theories about why this is happening. It’s possible there are other factors that the professor hasn’t shared with you, but it’s also possible that you are being treated unfairly (or both!). The chair can act as a mediator and will appreciate the information if it truly is a case of a professor trying to punish you rather than evaluate your work.