Ha - look around I also started something from Rachel - this is basically a scam - the phone number changes over and over so you never know this card services. I've also heard from Ann and Bridget. I've reported them over and over but because of the way the call (using fake numbers or because the number is always changing), it seems useless to report them. They are well known do a google search for Rachel, card services and you will find lots of stuff.
Some things I've done - I've pressed to talk with them and then talk nonsense or provide incorrect data. I've called the number back and you sometimes you can leave your number you don't want them to call back to - don't leave your number as they will use this to continue calling you - instead leave a number of some one you dislike immensively. I've done this with "crazy annoying" neighbor. You get a bonus - you irrate some one you don't like and you tie up phone lines from Rachel so to reduce bothering nice people.