If what you say is true, it completely constitutes theft. ...
But after all, we are classmates. Try to stay away from him. Usually, he only speaks when necessary. At other times, he will try to avoid it. Go to the library, but don't shy away. Just answer what he said to you naturally. I don't think his problem can be solved casually.
If you want money, you can't use tough measures or tone. You can ask his parents for it.