why can't my mom keep her promises???

whenever i ask my mom a favour and she promises me to do it, i want to be able to trust her. but it's just that i can't anymore. i trusted her to often, and i've been dissapointed MUCH too often.
I can't even ask of her to wake me up for school! yes, i have a alarm, but what will happen if my cell phone's battery is suddenly flat, or my cell phone is broken and the alarm doen't go off??
what am i supposed to do? can't i even ask of her to wake me up, when she's already awake?
it takes one minute to wake me up. just poke me and tell me, "Listen, you have to leave in half an hour, or you're gonna miss the bus." and i get up. it's as easy as that.
I don't have to put on make-up, because when i get up at 6 o'clock or 5 o'clock so i can leave at 6:30 am, i don't always have the time for it. when i get up at 5- yes. when i get up at 6-NO!
that's just the way it is. my brother is different. he just gets up by natural, without having to be woken up. he has a self-built-in alarm. but he can get up a bit later than me, too, because sometimes my mom can take him to school. we live in the country, you see, and my mother is teacher, and my brotehr and her go to the same area, but me- i go to school in town and my school starts at 7:55 am. it ends at 3 pm in the afternoon 4 times a week(sometimes 3 times) and only on friday and every 2 weeks on tuesday, it ends at 1 pm.
all i need in the morning is: a hair brush, a tooth brush, something for my hair, a cup of cocoa-
that's it! i pack my school stuff in the evening, i fix up everything the day before. i travel an hour to get to school-i have time to study then, too!!
but i can't even trust my mom on waking me up. i can't trust her on phoning my saxophone teacher, when i can't come, and i can't phone, because i've got school...
so when can i trust my mother? will i have to depend on my self in every section of my life, even tough she woke up since like forever and i started to depend on her?
did she loose her interest in me and in raising me?
and why, in heaven's sake, does it have to be during my puberty?!?!