Taken Advntage of............or not

I worked with a girl I adored. (do you still have crushes at my age?)
And yes there seems to be a recurring theme involving women, just remember I'm 27, so there are a lot of stories. I'm only sharing some.

So, back to the story, I worked with a girl I had a crush on.
We chatted, flirted, sent emails etc.

I'd asked her out a few times, and she'd been busy. It does happen. Then one day I asked her again and she happened to be busy....

Me: So, you wanna come see Ocean's 12?
Her: Sorry I'm busy tonight.......
Me: Dammit, well when will you be available for me to take out?
Her: Oh no Kal, I didn't realise you were really asking me out. I'm seeing someone.

**insert the sound of heartbreak**

Time passes, there is a work function, we all talk, drink and then she pulls me aside....

Her: You know Kal, sometimes just because someone doesnt do something it doesnt mean they don't want to.
Me: uh-huh
Her: Sometimes people have other commitments or they already made a choice, but it doesnt mean they dont want to do something, or that they're not interested...

And this was all punctuated with rubbing of my arm.

At this point, it's firmly clear to me she was interested, but was already seeing someone. Story of all our lives, we move on.

Time passes, people get promoted, change roles and suddenly she's working in a similiar position to me. And she needs help, I get asked questions (which is fine I get asked a lot of questions at work) and for my opinion.
She starts asking me for more input, we work together on a few things. Commended together, praised. And then I hear she gets praised for a few things. A few things I did the work on.

This point doesn't get mentioned of course, it's just not polite.

And we've drifted apart away from work, phone calls aren't returned. SMS answered an hour later with a 2 word answer......

Have things just changed over time? Or have I been taken advantage of?