I'm not going to help a classmate
Why wouldn't you help out a classmate?
He didn't like me and he always looked down on me, and I think it's my turn to hurt him.
even though he wasn't kind to you in the past, you should help him out. Instead of getting back at him, I suggest you to set an example by being nice to him.
Yuck, why should I help him if he looked down on me?
I'm sure your classmate will be grateful and reciprocate what you did. Try to be friends with him.