Have received several text messages from this #. When I text back and ask who it is and who they are trying to reach they do not reply. Getting very annoyed.

This number has texted me. Think it's a little strange how automated calls can now text.

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 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:

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

This number sent me a text "hello, please call.  They also have called from a local number leaving this number to call back.  They have harassed my son and daughter with a message saying they need to contact me, very important.  I sent a text back with no response.  Never called the local number and can only find that it is a landline.