I'm 15, my mom won't let my dad have custody, even though its what I want.?

I'm am 15 years old. I've lived with my mom for all 15 of them. January of 2010 my parents split up. I stayed with my mom. August of 2010 she found a boyfriend and picked up our family consisting of me, my little sister, and her, and moved us out with him and his two children. I lived in my hometown for 8 years. My mom moved me out with her boyfriend at the start of my freshman year because it was a better education from what I'd receive in my hometown. I hated my new school off the get. My mom wrote me a letter and told me that if I stayed and tried this new school for one year, I could go back and live with my dad in my hometown. My dad found a school that may be better then the school I attended with my mom. It's almost like a private school. The school has great opportunities. My father then filed for custody in April in hopes to have me in his custody by summer. In the mean time, early June, me wanting to live with my father for so long had such an impact on my mom, she texted my dad and said she's done. My dad and I win. I can pack my stuff up and live with him. She doesn't have the strength anymore. She watched me as I packed everything in my room and I wasn't allowed to leave anything. The court date ended up being near the end of June. After two weeks of living with my dad, the court date rolls around. In court my mother gets a lawyer and says she never granted custody. In the court they came to agreement that she'd have split custody in the summer, and my fathers custody is only temporary during the school year. I was crushed when I found out about every other week in the summer. I do not have many friends where my mom lives and I'm miserable. I'm so much happier in my hometown with my dad. Because of the untruthfulness of my mother, I've learned to hate her. How could she be so selfish to her daughter and keep her somewhere she DOESN'T want to be. I'm 15, have no criminal record, has a 3.9 GPA, and hangs out with a group of friends who have good heads on