I know you don't see how other interpretations deal with God's holiness and wrath towards the wicked. And I realize you cannot read Paul except through Penal Substitution Theory.
Based on our previous interactions I believe you to be an intelligent brother with a heart for God. I believe if you find yourself able to distinguish why others draw their conclusions then you will see how other ideas (like Christus Victor, Recipitulation, Moral Influence, and Ontological Substitution) deal with God's holiness and wrath.
Until then we simply have to be content knowing we believe the same gospel and have the same Father. You will just have to know that my understanding does with those things, even if you don't see how.
Hebrews 2:14-15 NKJV
Inasmuch then as the children have partaken of flesh and blood, He Himself likewise shared in the same, that through death He might destroy him who had the power of death, that is, the devil, [15] and release those who through fear of death were all their lifetime subject to bondage.