Au’ contraire, the idea of Middah k’neged middah is that Hashem is showing us that the punishment is a result of the aveirah itself. It’s not that He wants to hurt us because we were bad and “deserve” to be treated badly in return. As one of my rabbaim said, “Hashem doesn’t punish; He corrects.” The whole point of the punishment is to help us. When we do an aveirah, we are hurting our Neshamas. We don’t see it, but every aveirah affects our neshama.
Our whole purpose in this world is to meet challenges and grow from them so that our Neshamas can be on the level they need to be on to be able to go to Gan Eden and be close to Hashem. When someone does an aveirah, he stains his Neshama and his neshama is no longer as pure and it is not possible for his neshama to enter Olam Haba and have a relationship with Hashem.
Through “punishment”, the Neshama is cleansed and is now pure again and able to have a relationship with Hashem. So the punishment is Hashem’s way of helping us out when we mess up and don’t do teshuva. Everything Hashem does is out of love for us and is good.
Hashem brings the punishment in middah k’neged middah form in order to illustrate to us that the punishment and the sin are connected. It’s not that we were bad and t/f Hashem is giving us a potch. The point is that the sin had an actual effect even though we don’t see it, and the punishment is removing THAT effect that we caused so that we can be pure again.
I believe that the Maharal is the source for the above idea.