When can I call my ex-boyfriend that dumped me?

Stop it! You don't need this running around, you have far more better things to do with your time, as for him he just made that you found out his "game", before he could do any damage. Its a good thing you found out quickly, rather than your heart broken down the road, so don't subject to his games, playing "mind tricks" on you, you got out just in time. He's just made you found out before he could break your heart. GaMe over for him.

If its been a month and he hasn't even attempted to make contact with you then it sounds like it's over. I'm sorry but he isn't worth it. There's plenty of guys out there for you who are better and will treat you right. You just gotta find one. If an old girlfriend called him one day then he obviously still talks to her and him not wanting to talk about it to you definitely shows there's something wrong. It sounds like emotionally he wasn't all there in your relationship.

Don't call him anymore though! Everytime you call him you make it seem like you need him when you don't. If he hasn't answered then its not worth the energy you're putting into it.