Recorded message claiming to be "Rachel from Card Services"
I believe they are a major problem, using lots of numbers, pretending to be our credit card company, but actually spammers at best and perhaps identity thieves. They need to be stopped permanently.

Called the number back and it was out of service

Received a call in April of 2015.
No reply when I said hello, the caller hung up seconds later.

They called... I said hello...pause...then they hung up...i didn't call the number back.

Rachel does seem to be back even though the FTC went after her.  If you're on the DNC list please take a moment to file a complaint:

DNC Complaints
https://complaints.donotcall.gov/complaint/complaintcheck.aspx