I am 16, my ex is 20. We broke up a month ago (I broke up with him). We had only been dating 3 months..

Well now he is facebooking me, texing me, spreading rumours etc.
He is being super childish.

Ive deleted/blocked him on Facebook, and am changing my number as soon as my telephone provider is back up and running.

But what else can I do?
I told him I didn't want to talk to him or have anything to do with him and that we were over. Now he keeps putting me down and bringing my friends (whom he doesn't know) into it ("So-and-so said you have a new boyfriend)... honestly I'm just sick of it!

It already seems you are attempting to go No Contact which is the main thing to do. Until you can get your number changed ignore all phone numbers that you don't know.

As long as he is not crossing over the line into harassment or stalking there isn't much else you can do. Ask friends not to mention him to you and to ignore his games. Talk to your mother and other family members about his behavior so that they know what is going on.

If it gets worse or doesn't stop, you might need to look into getting the police involved. IF there is any danger that he might get violent or physical, know the laws in your area and what measures you can legally take to stop him.

It already seems you are attempting to go No Contact which is the main thing to do. Until you can get your number changed ignore all phone numbers that you don't know.

As long as he is not crossing over the line into harassment or stalking there isn't much else you can do. Ask friends not to mention him to you and to ignore his games. Talk to your mother and other family members about his behavior so that they know what is going on.

If it gets worse or doesn't stop, you might need to look into getting the police involved. IF there is any danger that he might get violent or physical, know the laws in your area and what measures you can legally take to stop him.
(Repspread)

Cat is right,and I agree,if he persists and you feel he is harassing you,tell your local police.