Just save the number in your phone and do not assign a ring tone to it. That way you will not hear it ring and will not answer it...thus saving your air time minutes.
I just had a missed call from this number on my CELL phone. There was no message left, and quite frankly I wouldn't have answered it if I didn't recognize the number. It is so ridiculous it's not even funny. I am constantly receiving UNWANTED calls, not only from this number but many others as well. It wastes minutes that we all have to pay for when it's our cell phones. There really should be a way they can be reported and the menacing phone calls stopped. Enough is enough already!!!