Hah! I found my bunny Mimzy when he was younger would chew his bars because he`d want let out! Once I let him out he would stop of course. He wasn't really into playing with toys at all. But he had a lot of wood toys, cardboard, toliet paper rolls, a treat ball would really distract him as long as treats were in it, baby keys, and those toys that dangle from the side of the cage. I suggest making a toy out of cardboard and stuff it with treats and hay so he has to work to get to it so it'll distract him for awhile!
He only really got into playing with toys in the past month (he is 6 months old now) and it turns out he has malocclusion which I think was part of the reason he chewed his bars. Maybe you could check his teeth and see if they're healthy?