got a mean friend...

hi,friends i've got a problem n i need some help....actually there's a girl in my class n she stays in same hostel as i do...she might be good at heart(being a bit polite to describe her) but she talks too rudely to me n my friend(also my classmate n roommate too)...during our class n practials she never talks to us... never even return a smile...but whenever we have to go for lunch n dinner at hostel's mess she turns up n says "lets go"...not only that we once asked her to get a book from library as my library cards were not available...her she was not getting any book for herself n i was in desperate need of that book i requested her a lot to get tht book for me but she refused n then after a long time when a atlast got that book she came asked for that book i didn't have a herat to say no so i gave it but i don't know how to deal with her....i just want her to be a bit polite, frienly n helpful...what do i do??? please help...