Three times today I've received a robo-call: "Hello, this is Rachel from cardholder services. There is no problem with your account…" By then I've generally hung up. We get these calls about once a week or more. The three times in one day was a bit much.
I Googled "Rachel" and "cardholder services" and got a long list of complaints of this scam and violation of the "Do Not Call" law. One example is "Hard to stop telemarketing calls from 'Rachel'", David Lazarus, Los Angeles Times, 2011-11-29.
Lazurus writes that Rachel is calling from cardmember services, but she actually says "cardholder services".
Cardmember services is the name of a legitimate company that services credit cards. The use of "cardholder" is a deception that many don't recognize.
You can file a complaint with the Federal Trade Commission (FTC) at https://www.donotcall.gov/complaint/complaintcheck.aspx.