See the beginning of the story in this thread “Can't believe I messed it up!".

I started flirting with this girl in the next class after taking the advice from PUA forum. She responded semi-positively and flirted back. She did surrender her phone number when I asked for it. I sent a text one day later but no reply.

Then the class had an evening party to catch up, she showed up with a guy friend who's 20 years older than her...We talked and I got to know a lot about her, while she asked lots of questions about where I'm from, what I'm doing now etc. She also told me she's leaving the city for Africa.

We laughed a lot and I touched her twice by hand and one time on shoulder. Later, I offered to grab drinks for some of the girls and was talking and laughing with people in line. She was checking me out with smile on her face. Later she and her friend were leaving and we shook hand. I grabbed her hand and said I'd take her out for dinner. She smiled and said yes immediately. So I said I'd text her later with date and location.

Two days later I sent this text. No reply. Then I called a few hours later and left a message. She texted back saying "no need for me to bother with dinner", but she'll try to meet up. It's 11pm so I texted next morning asking if she wanted to check out an art exhibit. No reply.

I was sorta lost and just waited till next week, when I gave her a call in the afternoon. She sounded quite surprised but happy to hear from me. I asked her how she's doing, and she said she's leaving the city this weekend. I proposed to grab a dinner anyway, and she said she should be able to find a time in the weekend while meeting friends for goodbye etc. We agreed she'll let me know so I happily got off. Dude you can’t imagine how charged I was!

It’s Friday afternoon, but the reply still didn’t come. My hearted started pounding faster and faster, so I called her twice (with 5 mins interval) and left a message joking that she should get up. Then I was sitting their doing my work but this idea of her leaving kept jumping in. I desperately sent her another text message boasting about the restaurant I wanted to take her. Then my phone beeped and this dreaded message popped up:

“Was at work. Sorry can’t grab dinner…my boyfriend isn’t happy.”

I was honestly shocked, but replied that it’s not a problem and wished her safe trip.
Guys, where do you think I messed it up? Is there any chance for me to bring back the situation?