Can I block SMS message from a number?

[PPCFreak]

Is this possible?
Verizon tells me that this is impossible but I find that very hard to believe.

What options do I have?

I dont have unlimited txt msgs and so far from someone that I don't know I have gotten 12 msgs in the last 15mins. I tried calling the number to tell them to stop. No one answers the number. I tried replying to one of the txt msgs and told them to stop. Didn't help. Txt msgs just keep coming.

VZW said my only choices were to change my number or report to the police as harrasment (like the police are really going to get right on top of that).