My teacher didn’t bump my grade.

I know it sounds entitled, but hear me out. It’s my sr year. Sem1 is ending, and grades got finalized today. I have had a 4.0 gpa all of high school. It is my senior year and my english teacher and me have had a pretty good relationship since freshman year. I go to a small hs and have had him every year for more than one class. He teaches all english honors classes, drama, and newspaper, all of which are classes I have taken. He bumped my grade freshmen year when I didnt ask him to for no reason. I didn’t mind tho. This year, he has been more hostile and forgot to update a 45 point assignment I turned in a day late because I was sick. The day grades were finalized, he said he would do it in the morning. He did not. I asked him at lunch and he said he would and didn’t. I have him 8th period. I asked him then to quickly update the grade because it was already graded on the paper, just not online. He said he would and waited for the last 45 seconds of the school day, when they were due. I had an 89.49, and at my school 89.5 and higher rounds up. I was so upset. The final bell rang meaning my grade was finalized and he said he accidentally entered it as 4/45 instead of 44, which is what i got. I pleaded to him and he said there was nothing he could do. I talked to the grade manager and she gave me a note for my english teacher to sign. He said he would give it to her herself signed. I got an email from her today saying she didn’t receive the note and my final grade in the class was a B, destroying my 4.0 GPA.