How do i stop being friends with a needy and annoying person?

This girl has called me every single day of my summer at least three or four times and left a message each time. I never responded back to any of her calls. She emails me all the time and ims me but i delete the emails or get off of im. She doesn't know how to take really big hints i guess but what I am worried about is school which is this Thursday b/c i know she will find me and bug me some more. How do i get rid of her? I told her before the summer started that i didn't want to answer the phone b/c i didn't want to talk to her but she didn't even get mad.