Contact your cell carrier and report the number as a nuisance number and request it be blocked. Inquire if they offer a service to black list numbers so they can not call or message you at all, Verizon lets you block up to 5 for free.
Also inquire if you can forward the text to 7726 aka SPAM:
http://www.fcc.gov/guides/spam-unwanted-text-messages-and-email
"Do not respond to unwanted texts or emails from questionable sources. Several mobile service providers will allow you to forward unwanted spam texts by simply texting it to 7726 (or “SPAM”) to enable the providers to prevent future unwanted texts from the specific sender. "
If you have a smart phone, there are many anti-spam apps. Check your phone's app store.
At 5:12 AM today I received the following text from this number:"Here's the easy adult singles web page I mentioned to u at class Grover, FunCasuals.COM. I played with 3 babes this-week, way simpler than pubs;)"
At 12:29 PM on Apr 06, 2013 (yesterday) I got the following text from this number: "Here is the sexy casual hookup web page I mentioned to you in dinner, Colin, FunCasuals.COM. I met up with 2 ladies last-week, much easier than bars ;-)"
At 1:00 PM April 7, 2013, I received the following text from this number. "Here's the easy adult dating web site I mentioned to you in work Blaine, FunCasuals.C OM. I played with two women this week, much less difficult than clubs;)
"Here's the easy adult hookup web site I told you about in the gym Ian, Funcasuals.com. I picked up 2 girls this week so much less difficult than bars ;)"
I received this text. "Here's the easy adult hookup web site I told you about in the gym Ian, Funcasuals.com. I picked up 2 girls this week so much less difficult than bars ;)"
I don know how they get this number.