Said they were from the Mergis Group and calling b/c they saw my resume on Career Builder. They asked me to call back same day but I wasn't able to call until the next day. Then "the number you are calling is invalid." I'm pretty sure I don't want to do business with someone whose phone number doesn't work the next day!!!
The Mergis Group appears to be a real recruiting agency with offices in a number of states. Their BBB ratings vary profoundly from state to state, but seem all to be based on very little information. There is no BBB information that I could find for their office in the 314 area code, but there is an office in that area easily found on Google. However, it does not have the same phone number posted in these complaints.
Google turned up this physical address, phone number, and email address for the Mergis Group in the 314 area code:
1610 Des Peres Road Tel: 314/659-4226
Suite 190
Saint Louis, MO 63131
Since the telephone number appearing on your caller ID does not match the number I found for them, you might want to call the above number (Google for it yourself or otherwise convince yourself it is the right number, first) and ask if they use or have ever used the number on your caller ID. You may be able to confirm whether the call was ligitmate or just a phishing expedition. And if it is legit, you may be able to talk to the right person, if you still actually want to do that.