In regards to >>8
(Even if there's no way to have your phone # changed, you should easily be able to block her number, if you really want her out of your life...

If she's not capable of being mature (and given her age and your age, from the other posting referenced by >>10, she should be the more mature one, if anyone, then there's no future in this relationship...

If you truly wish to break this off, then just block her phone calls, block her e-mails, and drop it; But it seems like you don't fully want to...