How is this even possible?

So about three weeks ago I had to block one of my friends from my phone because they where sending me rude texts and just talking down to me and I was tierd of it. I blocked the number and yesturday they text me phone this long message and I thought at first maybe they changed there number by like one number but I looked on my Verizon account online and it says that the number has been blocked and the block won't be up until April 17,2013 I made sure it was te right number and it was so I'm extremely confused on how they are texting me. Does anyone know how they are doing it

Oh yeah and I have an iPhone and I have Verizon service and they also have an iPhone if that helps