Alternative result could be that they are actually nice and their phone ran out of battery or something, as mine has a habit of doing when I need to call someone.
This case, maybe she isn't that nice after all and really is just ignoring you. But that doesn't dictate future cases - doesn't mean that others won't come along who genuinely want to meet up, just this one's not so good. does the saying "to dodge a bullet" fit here?
There'll be nice ones, they're just taking their time :/