Grades are bullshit

There's is a school dance tomorrow night for me. I had two D's and two F's four days ago. I got both F's up to a C and one D up to a C. Yet my parents are debating whether or not to go off my quarter grade is my semester grade. My mom told me that is I got my QUARTER grade up. Then my da jumps in and says that we need to go off of my SEMESTER grade. I think this is total bullshit!! Shouldn't my parents take in the fact that I worked so hard to get my grades up as high as I did in only four days? My best friend is going to be waiting for me and if I never show up it'll be my fault that her first dance was fucked up.

Edit: welp. Turns out I'm not fucking going. So I just checked my grades and all of my D's are up but my parents still aren't letting me go...