I'm sure the tech just missed it. They'll fix it up. It's just the guy at the desk just didn't like being flipped out on. The first reaction is defense. It's a sticker item, they have to fix it. that's the law. You would have gotten a different reaction if you didn't freak out on the guy.
The poor bastid at the desk:
a) didn't sell it to you
didn't put the sticker on it
C) doesn't know if your mechanic knows crap.
Don't flip out on him until they have a chance to look at it.
Can you tell I've been working the service desk this week? I've got some stories to tell...