000-003-9858

Has shown up a number of times on wife's text log. She has received texts from this number and then has sent a text back. WTF!!!

For 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=com.privacystar.android.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.
http://www.att.com/esupport/article.jsp?sid=KB115812

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

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:
https://800notes.com/faq/state-do-not-call

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

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

Did you ever find out who this was ?? Or what?

Did you find out anything? My husbands phone has the same number and he has responded as well.