[BDF]

This sounds like a complicated issue. Tbh I myself don't know what to say really. I think you're going to have to go over there as some point, or meet him face to face. I assume you go to school. Your school should have some professionals that might be able to help, I mean it's a genuine problem if you've lost all your books and equipment because of him, so they should help. It takes some balls to make a move like it, but I don't see many other options for you. It doesn't sound like your mum has a lot of power over the situation.

I'm not really clear 100% what's the position with your stuff though. Where you moving from his place, and now he won't pay for the move, so all your stuff is just staying at his house?