Is it not possible that this is just spam, and has not been issued directly from the retailer in question. Perhaps the retailer's systems are not as secure as they seem, and a phishing type operation has access to his client database?
Either way, under no circumstances should you place CC details on an email, and I would contact the retailer directly as to your concerns in this matter.
Either way, under no circumstances should you place CC details on an email, and I would contact the retailer directly as to your concerns in this matter.