I've read your comments but I'm not sure whether the problem was her, you or circumstances outside the control of either of you.
She asked you to text but you called.
The call was "dropped". What does that mean? You lost signal, she lost signal or she answered and then put phone down?
She pretended not to hear? How do you know that? As you didn't make contact 20 minutes before, maybe she didn't think you were coming.
So maybe you're right, and she did let you down, but the story you've told leaves a number of questions unanswered, a number of doubts.