this sounds strangely like my situation, but mine had a bit of a more twist, she was bisexual. But at any rate, it sounds prtty much what happened with me but we didn't talk on the phone that much. Perhaps her excuse is genuine? I would suggest what the person before me said: if she continues donig it .. its rude and tell her that it isn't really respectful or something like that. Just keep trying, and try asking a lot more indirectly. and see what her responses are. that method can really tell you if she wants to do somethnig or not. It has worked for me a few times. good luck!