Chat with a personal injury lawyer.
But keep in mind what ER doctors call motorcycle riders:
donors.
Hope you're recovering from your injuries.
Is there a law in the state / province where you live that requires all motorcycle helmets to be government certified like where I live (BC)? If so, you may have a case if they are selling illegal helmets. If there is no such law I doubt there is much you can do. Talk to a lawyer.