"Rachel" from "Cardholder Services" -- it's a scam where they promise you lower interest rates on all your credit card accounts. Once you give them your account numbers, they rape you and leave you hanging out to dry with your creditors.
I didn't answer and they didn't leave a message. A search of the area code and prefix found that the call originated in Lenore, Idaho. I don't know anyone from Idaho at all, so I'm sure it's a solicitation of some sort.