I think that maybe you should take a step back and examine how worth your time building a relationship with this girl is. I dont know her, but maybe she feels like she needs a bf and someone else to keep waiting, I dont know. (Im not trying to be mean, but some girls are that way) If I were in your shoes, I would let her make the attempts to get together or to talk on the phone for awhile...not ALWAYS, just let her miss you a little. And, heres something else to consider-you could try asking her why your relationship is that of a bf/gf without the actual title/intimacy. Good luck!