Do you know how it happened?
I know my friends Sundia Shining's axle snapped in half due to abuse.
What diabolo is it?
I've stripped 3 Finesse and a Taibolo axle, all of which were replaced by finding the right size at the hardware store. I guess you could do the same. Easy fix.
I don't really know anything about bending it back though. I guess you could try, um, pliers or something?