I know there's been a few posts about this already, and each has received the same copypaste response that steam has made an error, but is Spiral Knights taking no responsibility on it? Due to the advertisement's time sensative nature, it qualifies as false advertising.
http://i26.photobucket.com/albums/c129/Alexxx01/battlepack.jpg
You really should have it sorted out before a formal complaint is lodged.
Yeah, some kind of public statement really needs to be made about this. So far there's only been one random post buried in one random thread.