Hi all.  I was having this same problem, they were calling numerous times a day.  I called Verizon in an attempt to have the number blocked.  Unfortunately, cell phone companies do not yet have the technology to block individual numbers.  However, if you tell your provider that it is a harrassing phone call ( which it is) they will most likely allow you to change your number for free.  

Long story short, Verizon changed my number for free :)

Hope this helps.

CALL 911 THEY WILL TAKE CARE OF IT ,
I DID MINE LIKE THIS , THEY ASKED ME THE NUMBER OF THIS COMPANY , AND THEY WILL TAKE CARE OF IT

Calling 911 when it isn't an emergency isn't a very good idea,those lines need to be kept open for people who are really in need of help.  You can always get the number for the local police department, if it is that serious.

The local police dept just told me to call the phone co.  The phone co told me they would report it to the FCC.  I am still getting a dozen calls daily.  I just hang up.  I just now called the 1-888-868-0848 number and a male voice responded.  He is a foreigner with an accept so thick I could not understand him well.  I did get the info that it was a Grant Funding Source. I demanded he stop these calls immediately.  I hope it happens.  Just thought this info might help someone.

If you are with AT&T, you can get the parental control add-on, which allows you to block a list of numbers.