what to say to get your ex boyfriend back

So how to get your ex-boyfriend back recently?
My bf and I had a fight and broke up three days ago. He still is not saying why you want to break, but says "you know what I did not want to talk about" how do I fix this and get to get back out with me? And yes, I asked again and again I did, but he repeats that line. I also said I have done everything that could have been potentially harmful. How do I resolve this and get her out again?
Why custom He said what was supposed fact, that seems a bit childish – maybe doesn't have a good reason. But anyway I have broken with the same man three times and returned with him after toghter each (time dont ask i know its bad) honeslty what I learned is that giving space – much of it. I know its hard but stop talking to him for a while – a month or at least a couple of weeks. Then call him and be really happy and say that life has been impressive talk about something thats exciting past (even if they beautify U). basically be the girl asked to begin to with. then some say it would be good to keep in touch with him, who will miss his friendship u – but do not dwell on it. keep really short and be happy! belive me its worked for me every time! stay strong to keep busy, and belive me you can find another guy who U are best if doesn't work out