Breakup are tough for both the dumper and dumpee. I broke up with my girlfriend a few months ago so I can give you my perspective. She doesn't want to talk to you part of the reason could be that she doesn't want to bring back the feeling she had for you. Maybe there are trouble in your relationship that you are not aware of.
The way I think about it is if I started talking to my ex and be friend then it would cause me more uneccesaray pain. It's better for you to leave her alone and if she decided she want to talk to you she will.