Even if she did it only once - it may be true that she is busy, but if she does not reschedule the date it is obvious she does not want to be with you.
2. She didn't introduce you to her friends
If she accepted the date but calls you from time to time (when probably she is bored), or introduces you to others as a friend, this is a clear sign of rejection.
3. She mentions another man
She talks to you about another man - it is clear she thinks of him. The same, if you are with others and she flirts with somebody else, it is a fact that you are unimportant to her.
4. She avoids being alone with you
She meets you only in public places that are crowded, she doesn't let you take her hand or kiss her. If you invite her to your place and she refuses - she is not interested in having a relationship with you.
5. She does not answer your calls
You call her all the time but she doesn't. For your own good, understand that she does not want a relationship with you. Show dignity and move on.
