If you acknowledge their call in any manner, it just tells them they have a live phone number. They then sell your phone number to another scammer as well as continuing to call you. NEVER respond in any way to these calls, just ignore them or block them but do not respond or you will never get rid of them.
Card Services....again! Looks like a new number as I didn't have this one blocked. I heard they get paid by the call as long as they get through, even to an answering machine. So block those calls people till we get rid of Rachael once and for all!