I don't see where it says you get the coke or the coozie, but you have to tell them why you were confused about coke zero tasting like regular coke. It looks like a lawyer is going to sue for your taste infringment. I cant guarentte you will get anything but it looks like a real coke site and they will probably send you a free 20 oz coke at the least.
Many people have received a coupon for a free 20oz Coke Zero, Coke and a Cup Coozie . I will post back if I receive my offer.
https://secure.suezero.com/ssldocs/contact_form.jsp