Do consider maybe getting a call blocking device or phone.. You can google them and many are around $60.00 or so.

Report your callers here, not just to the DNC alone:

https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
https://complaints.donotcall.gov/complaint/complaintcheck.aspx?panel=2

By State DNC lists:
http://800notes.com/res/DoNotCall.aspx

FCC Abandoned Calls Complaint form:
http://www.fcc.gov/cgb/consumerfacts/1088D-R.pdf
email:  fccinfo@fcc.gov

To file complaints on Foreign company's:
eConsumer.gov: Report Your Complaint
E-mail: econsumerwb@ftc.gov

Called my work number and did not leave a message.

I called the number back. There is a different man's voice who says "You've reached Jim. If you leave a number I'll call back. " This voice has a distinct Southern twang. I can say that because I'm from the South. But I would not put it past this scammer to be faking a Southern twang.

When I picked up the phone I said Hello. He said hello and then said " I think I've got the wrong number." By the time I had said: "Well what makes you think that?" He had hung up. I was going to make some crack about Warren Buffet. Oh, well.

From my past experiences it's a telemarketer.

I'll be on the lookout for a return call.

Picked up receiver and did not speak.  Recording said "Hello.  Hello.  I believe I have the wrong number." and the call disconnected.  Only showed Omaha NE & phone number on caller id.

I just called the number from non-callable Gmail. Got "Jim's" voicemail. I left a message that I think I dialed the wrong number, and hung up. If you have Gmail without a voice number attached to it, you may want to say hello to him as well. :D