why she contacts me?

Hello,

i had a breakup about 1 year ago.. my gf asked for it.. i tried very hard to convince her but she was quite firm...actually she is very egoistic from beginning only and it was very difficult to deal with her... few months back she had a engagement (with her first cousin only!!!!)... since last few weeks she tries to contact me.. even messages me asking that can she call me... but i don't reply at all... so now i think she is trying to chat with me under different user name...she tries to convince me that she was never at fault.. it was a clear case of betrayal from her... when i used to contact her,she didn't used to reply.. now when i don't reply her or contact her, she tries to contact me.. why she is doing such? ..we were in relationship for 4 years..