called yesterday 6 times and has already started calling again today

May be calling from multiple numbers, multiple prefixes, etc. If it goes to the answering machine, they don't leave a message. If we answer it, they hang up.
http://800notes.com/Phone.aspx/1-201-345-8169
http://whocallsme.com/Phone-Number.aspx/2013458169

Call multiple times a day.  Hang up when I answer.  WHo are they?

This number called my wife's cell phone, 11 times on saturday starting at 8:50am and finally stopping at 8:24pm. No message was left and when she answered the line disconnected. I was tempted to answer the phone my self and tell them off. I called and got a recorded message with a male voice.  Somewhat garbled,  Press 1 for customer service and press 2 to be placed on the do not call list.
My wife did sign up for some marketing surveys and such recently.  We believe that this may have gotten her number on some list....but 11 times in one day, several in half hour intervals, is harassment,

No message left. Returned the call- does not say the company name only "press 1 to speak with a customer service rep, press 2 to be placed on the do not call list". I pressed 1 several times and the message just kept repeating. It said once or twice it was connecting me with CS but never did. Finally I pressed 2 to be on the do not call list. I believe this number has called before and I have requested several times to be placed on the do-not-call list. From the past this one might be selling some kind of diet pills.