why is she calling me in the middle of the night ?

So i talked to this girl for 5 months we saw each other 2 times in real life,

but after the 2nd date we never saw each other anymore but we talked on skype alot and i called her alot

but after a while she lost intrest i think she didnt want to see me no more her excuse was her school,

and we got into a couple of fights she said to me that she is not intrested in me and we dindt had contact for weeks but then she would call me again to apologize,

but after the third time i really got angry i said to her if she is not intrested and if there is no future she should leave me alone and dont try to call me anymore because i do love her , so she was cool with it,

but now after 2 weeks she always calls me up in the middle of the night at 4 and hangs up

whats up with her? i dont know how the female brain works :P