Um,

I dunno. Its 15$. How much time did you spend writing that email?

Also, while I understand your frustration, since you have chase continental card, you are exempt from fees - you should have pointed it out to the agent. If you didn't *think* you were exempt, weren't charged for it initially, and then charged later - well, them's the breaks, sometimes you slip through the cracks, sometimes you don't, and complaining that you got to slip through cracks initially is, well, bad.