Cheers bud, I got in touch with the cops and they've given me a ref. number. Might not bother to be honest, it has just sickened me. The trouble is I don't have enough space to keep it in the flat so have to keep it in the stairwell, so I bought a decent lock. Turn's out a decent lock isn't much use when they saw through the metal bannister to remove bike, lock and all. There's nothing to stop it happening again, so I'm not sure I'll bother.