Perhaps you should study the theory a bit more.
Scripture does state that "the LORD hath laid on him the iniquity of us all."
Isaiah 53:6. But all Christians believe that the Lord has laid on Christ the iniquity of us all. That is not the Penal Substitution Theory of Atonement. That is just common Christian belief.
You can't just pull out parts of the theory that is in Scripture and claim the presence of Scripture in the theory proves the theory correct.
Penal Substitution Theory holds that God punished Christ for our sins instead of punishing us (which is, of course, not found in Scripture).