Is there any possible way to block a number on an At&t iphone?

Okay so i'm 14 and this one person who is fake (its probably one of the girls who hate me) keeps messaging me and won't stop. And i'm getting sick of it. Is there a way i can block the number from texting me?

Yes you can have your parents contact AT&T by dialing 611 from your phone and they can block the number

You can also use a service like http://www.seeblockednumber.com to block callers and manage your blacklist.