AHHHHH! help?

so my best friend of TEN YEARS (i'm 15 by the way) is acting really meanly. i went to lunch with her at school today off campus, and i'm pretty sure i left my phone in her car. I can't find it ANYWHERE else. so i told her i would go by her car after school and get it. when i ped her in the hall and reminded her, she was like "oh, i'm leaving school now." by leaving she meant skipping her 7th period cl. so i texted her from my friend's phone when i got to cl and asked her to put it in my locker after school, but she said she didn't have it when i KNOW it's in her car. and she's usually my ride on fridays, so i had to get a ride from my mom home. now, i don't have a phone, and it's six o clock. i've called her five times from my house phone and left her two voicemails, and she didn't call me back. i've called all my other friends who's numbers i remember. i'm SO angry. is there any way for me to release my anger? and should i act llike a bi(t)ch when i talk to her about