My boyfriend said that he hacked my QQ after breaking up, but he still returned my mobile phone message. Why? Is there any chance to make up?

First of all, you should know that hacking qq can only explain temporary anger, not anything else.

That depends on what information he replies to you. If he answers your questions casually, or just hits you, it means that he is no longer interested in you, but fortunately, your image cannot be deleted from his mind, and he will still care about you. But if he breaks up, the relationship will be hard to recover.