I Trusted And Went Out On A Limb Hoping To Make A Friend...

I am a college student who had a really good part time job, I'd been there 1.5 years. My job had an opening. I thought I'd announce it in class, to help someone. Also, maybe to make a friend :)  I told the professor and made a few announcements to classmates.   A classmate told me she was really interested.  I really tried to push that she get hired, i took her to the agency to help her with the application process. I even pushed for her to get top pay and start making what i was making, without experience. She got the job. The first month i stayed out of her way, friendship & work dont mix. I noticed though that she never came to say hello on break nor ask to go to lunch together. At school things were different, she was polite... but I noticed there was no additional 'bonding'. After a month, she finally decided to talk about work at school... they told her not to come in, it was slow. At work, I asked & encouraged them to ask her to return. They told me there was no additional money in the budget. Being in accounting, I crunched numbers, closed out open PO's and money was made for her return. I was soon to start a mandatory internship through school & decided it was time to leave once i started. No known date. The next day she was sitting on my desk, returned from the absence & I said hello, what was up that she was sitting at my desk... she said they called her in and I'd be training her because I was leaving soon. It was uncomfortable, I waited to talk to my boss, she didn't come in at all. I trained my her thoroughly. The next day I was fired for no reason. That is fine, I've gotten over the job thing... see school is #1. I was going to be leaving soon for my internship anyhow, so I wasn't upset. What is bothering me? Here it is: Three weeks past and my classmate has not called me to see how i was doing. Spring semester formally started & we have not been speaking in classes for 2 weeks now. I had been happy she got the job, but hurt that again, as much as i cared to help her... she hasn't cared to reach out & even ask how i have been. Feelings of acceptance that she got the job, have grown into feelings of hurt & being used & abandoned... looking back, I am seeing that she never cared.
Am I correct in feeling this way? Would someone point out to me if I'm wrong & show me what I'm not seeing... or are my feelings of betrayal valid?