A lady from this number called me and wouldn't leave her name or a number for me to return her call(my brother-in-law took the message). when i try to call it back it doesn't even ring.. it is just silent. Who is this calling?

Received a call from this number from "Card Holder Services."  A recording stated that my eligibility to lower my credit card interest rate to as low as 6.9% would soon expire.  The recording did not indicate who in the household was being called nor which credit card company.

they hung up; when i tried to call back it just rang busy over and over!

call with no message

Left no message.  Just hung up.  Tried calling back and it just rang and rang.