Free will is inescapable. Without it, you have no ability to assign moral blame, which means law and order become impossible. If someone punches you in the face unprovoked, you are just as responsible for putting your face where his fist was going to be. Thus, there's no justification for your attacker to be rehabilitated rather than you, an innocent victim.
Your issue is not with free will, but with retributive justice, ie. the argument that moral blame deserves punishment.
Your issue is not with free will, but with retributive justice, ie. the argument that moral blame deserves punishment.