Would you ever give a guy a fake number?

[unknown]

This girl and I have been having small talk every time I go to her work. After two weeks I got the courage to ask her out and she said yes wrote her number on my receipt. I called her today because I wanted to go to lunch with her, and the number is disconnected or something. I tried texting it and nothing happened. I'm pretty sure I have the correct numbers typed in. We're both 19, and I feel really bad. I ended up going to bed and sleeping for 6 hours instead, trying not to think about it. I have her on facebook but she NEVER gets on there. Do you think she accidentally wrote the wrong number? Should I try meeting up with her again and mentioning the number doesn't work? Or did she do it on purpose?