AITA for stealing "her" opportunity ?

I (17f) am in my final yr of schl. So a few students (5) of our class have been given the opportunity for an educational trip. Well, this trip would be really helpful for the course i hope to take up in my college. This trip is also only for students who take up the top 5 ranks of our class, which, i come under. So, genuinely, i thought i was going. But, it was slotted to 3 boys and 2 girls. And as soon as they heard abt the trip a girl from my class personally reached the teacher and said she wanted to go. So when teacher told me and one other girl (the other girl is one of her frnd) is going she told the teacher to exclude my name and add hers and so the teacher did. I did not come to know of this until yesterday. When i came to know i was so mad but i did not ask anything. The exact reason for my anger was that this trip was not even related to the course they chose for their college, it is literally the opposite. They just wanted to go together as for fun. But i did not say anything as i am not a confrontational person. But later another person came and asked why i was excluded and i told her everything abt not knowing that i was excluded up until that time. And the teacher noticed it, and asked me. So i told her everything again. So she told me that she thought, i agreed to be left out. So i told her i wasn't. So she changed the whole thing and added me to the trip.

I only really want to go because it is really really helpful for clg and no other reason. But the girl who is now excluded is mad at me for taking to the teacher instead of asking her directly. I told her that it was rightfully mine since i have the rank and she was the one who first took it directly to the teacher.And she is mad. Now all the other girls side with her and say that i shouldn't have talked abt rank and belittled her. They want me to apologize to her... But i don't want to.

So, am i the AH here? Should i apologize?