Um, I can't say whether the guy should've been fired or not, but you just don't do that in customer service. You just DON'T. OP had every reason to let someone else at AP know - it was Absolute who decided to fire the guy (if indeed they did)

If anything, you had more reason to be fired, what with the shouting match. I've been there (worked in a department store myself in high school), I know how it is. Sure, you can snap, but don't be surprised if you do get the boot - no matter how much of an asshat the customer is.