Hi Dal,
I'm with Phoenix on this one (mostly). If this girl is someone who sits near you often, talks to you, touches you,..feels that comfortable with you,.....and then can't respect you enough to just tell you ,"Sorry, no thanks".
No, she gives you a fake number,..let's you leave all happy, just to get your feelings stepped on when you try to call?!?!?!?!!?!
That's not just wrong,..it's intentionally hurtful and mean-spirited.
If you have to deal with her,..then you have to deal with her,..if it were me, I'd let her know that she's a real piece of work. I would have no problem letting her know how I felt.
If you don't have to deal with her,..don't!
Good Luck!
Jerry