Called and hung up, no message.  If you return the call it says "not in service"

I never answer calls I don't recognize. They didn't leave a message.(Red flag)!

They don't answer, hang up as soon as i answer. They leave no message and they keep calling

Have been calling the last 2 days. When I answer they hang up and when I call them back says this number is out of service. One time it went through and a lady answered and denied anyone making phone calls from that number.

Its totally possible too..

phone spoofing explanation
http://en.wikipedia.org/wiki/Spoofing_attack
http://www.fcc.gov/guides/caller-id-and-spoofing
*****************
http://consumerist.com/2014/03/18/florida-den ... y-telemarketer/
http://800notes.com/forum/ta-9f0ce767d8019be/a-different-spoofing-victim
http://www.foxnews.com/us/2014/07/26/colorado ... er-id-spoofing/

Consider getting a call blocking device or phone.. You can google them and many are around $40.00 or so. If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number. For tracfone & straight talk:

https://play.google.com/store/apps/details?id ... .tracfone&hl=en
http://extras.straighttalk.com/en
http://www.youmail.com/home/carriers/straight-talk/block-number
https://www.straighttalkwirelessforum.com/viewtopic.php?f=6803&t=55006

For text messages: forwarding any text message spam you get to the short code  “7726,” which spells “spam” on most phones, to alert your network operator to the abuse. ATT won't accept 7726 But they will accept BLOCK and return a message that the web site is blocked. forward the texts to 7726 or BLOCK, depending on your phone carrier.

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

To file complaints on Foreign company's and scams:
http://800notes.com/forum/ta-d20d86fdc3e145c/reporting-international-scams
https://www.econsumer.gov/#crnt
eConsumer.gov: Report Your Complaint
E-mail: econsumerwb@ftc.gov

Federal:
https://www.ftccomplaintassistant.gov/#&panel1-1
https://consumercomplaints.fcc.gov/hc/en-us
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