Plz hlp!!! my bff moved and stopped calling?

my bff,christin moved about 1 year and 1 month ago and i would call her and we would talk for like 2 hours on the phone. she is 45 minutes away and both our parents work full time so we can rarely hang out. she never calls me back because she apparently doesnt call anyone back. ive tried reducing my phone calls to like 1 time a week, then 1 time evry 2 weeks, then stopped calling her all together, to try and see if she would care enough about me to call, and she still has not called me back. should i call her and tell her that if she isnt committed to being my friend still, then we shouldnt be friends? or should i call her and talk to her like we are still bffs? or should i wait it out? wat should i do? plz hlp someone!!!