First time posting sorry for long post, TLDR at bottom

So here's some context: In the beginning of the semester, my girlfriend signed us up for the anime convention in her uni. This anime convention was going to happen on the end of my spring break, which is next friday and the weekend. She signed us for to volunteer for it because then we would be able to get free access to the anime convention on all 3 days. However, we abandoned the idea of volunteering because we were required to participate for a training session and it was a little difficult for the both of us to attend, since the training dates were during my break and during her class. We decided to pay for the tickets, but didn't actually buy them because we forgot and by the time we realized, they were already sold out. My girlfriend got really sad because her school requires her to take her spring semester off after her sophmore year, so she wouldn't have the chance to go to this convention until she graduated. At this point, we were both devastated and since she was stressed out and down from other factors recently, I decided I would do something to make it up to her.

Around a month ago, I started gathering people to ride with me from our uni to our home city, which was a seven hour drive. I told them that I would start this morning, and leave to go back to uni on sunday the 24th. When I arrived, I dropped everybody off and then I got an email from her uni, reminding me that we could still sign up for the volunteering training dates, which meant that although tickets were sold out, we could still get the free pass in order to attend the event. This is where things get tricky: the training dates were for next tuesday, wednesday, and friday. I had already told my friends that I would be driving them up on sunday, but I really wanted to make up to my girlfriend, something to give her a little boost. 

I chose friday for the training date, but I knew I was basically intentionally screwing over my four other friends and I felt really bad. I was basically going to drive up on friday, and leave them there or force them to come with me, so I told them that if they felt like staying until sunday instead of coming up with me on friday, I would pay for their ticket back to uni, and also carry their luggage in my car for them when I drive up. I also won't  be charging them for the ride down since I feel really bad. 

Is there anything else I could have done for them? AITA?

TLDR: forgot to buy tickets for anime convention, they got sold out. Volunteering gives free access, and it falls on a day that makes me ditch my four friends and leave them stranded in order to get said free access.