How to block someone's number from texting you?

There's this person at school that got my number and keeps texting non stop that it's annoying. I told that person to stop but they won't listen.

Is there a code I need to to text to a number or something? I have an iPhone and my carrier is Verizon.

I think deleting their number might help, if not call customer service

Log into your Verizon account on Verizon.com and go to your block list and type that number in. Blocked!

Contact your service provider or for laughs
Text them this "Your number has been blocked any further contacting of this number will result in a $1 charge to your account"
And if they text back after that just say back "$1 has been charged to your account"