Tell Gamecock, as he doesn't believe that satan knows, that is the reason for my reply.
I don't understand why the punishment, as satan is only doing as he was knowingly created to do.
This is where you are going off the rails. You are imputing to God responsibility for the decisions we as created beings make, with the rationale that those decisions are a result of how we are made. This is the same argument used by many homosexuals. It ignores the fact that man is a self made soul in the sense that who we are and what we do is partially based on all of our previous decisions. Every decision makes a subtle change in who we are, and the sum of those changes equals who we are "right now."
G-d does not live in the dimension of time. It has been oft speculated that we do as it affords us an opportunity to be changed before we leave "time" as all of eternity would be like "now."
To us it seems somewhat paradoxical, but I'm willing to give G-d the benefit of the doubt as I can't see His side of the equation.