I also was given a rental car when I was 21 because the dealership didn't bother to work on my car when they said they would. So I got stuck in an auto Aspire.
Be a pain in the butt about it, they'll get you in a car. Don't settle for an Aspire. I was 21 so I first stopped at the liquor store on my way home to drink away my sorrows (at being seen in an Aspire).
Call the dealership and tell them that since you weren't given a rental car you'd like them to pick up the taxi tab.