+1 on the credit card chargeback. In my experience, if a company isn't responding to my calls/emails, they always respond when the credit card company gets involved.

I wouldn't take it out on the IC brand though - I'd just make a point of avoiding that hotel and telling them I'm doing so. I really do hate it when hotels put miscellaneous charges on your card and they don't tell you.

Please name and shame the hotel too!