How to block someone's calls and texts from my iPhone?

So my ex boyfriend won't stop calling and texting me and it's really pissing me off. I've been ignoring his texts and calls for the past 2 weeks but he still doesn't seem to get the hint. I don't claim to be the most tech savvy person in the world, so any clear, easy to understand, step-by-step procedure on how to block a number on my iPhone would be greatly appreciated.

Sorry Katherine you can't block the line with your phone but your service provider can. So call your service provider and ask them to block the line.

I don't know but I'm answering to get points