Hotpoint WMA64 Drum & Pulley wont spin?

Hey,

I've been trying to fix my washing machine, it recently stopped spinning so i took it apart to replace the drum belt however while trying to put on the drum belt I relaised that the drum pulley nor the drum will spin, I have tried forcing it to move but there is very high tension and I can't get it to move an inch.
There are no clothes stuck in the drum everything seems fine.
Anybody know a fix or what's wrong?

Thanks.