I called back and all I got was, "Hello. Thanks for calling. If you would like to be placed on a Do-Not-Call list for the number that just called you, press 1 now. Thank you."
I received a call from this number telling me I would have my interest rate dropped to 6% for paying on time for past 6 months. He said he was from Chase, Bank of America, Citibank. He asked me to verify my expiration date to make sure my credit card was not cancelled. He hung up on me when I got suspicious and started asking him more questions.