If she expects you to behave in a certain fashion, I.e be in contact, she should behave the same, its basic manners, treat others as you expect to be treated, especially in a relationship with someone you are supposed to care about. How long does it take to send a quick text, 30 secs top, she could do that whilst sat on the toilet.
Sorry dude, 2nd post about your relationship/girlfriend, i am sure you dont need me to spell it out you