What do you do when you punish your 4 year old by taking something away, but he acts like he never cares?

Every child is different and some honestly dont care and would rather lose something and behave, that shows that it is not the proper type of discipline for them because it has no effect on them. If he says that he doesnt care about one punishment, tell him that with that attitude he'll lose something else, say "fine, you dont have to help your sister, instead I'll take your wii and you can go sit in your room with no toys or games until you are ready to apologize and say your sorry", then go make him sit in his room, no playing or anything, until he apologizes and does as hes told, hoe long hes in there is up to him, it could be 5 minutes or an hour, maybe even longer, thats up to him, but keep him in there until hes dropped the attitude and is ready to behave. When he sees that your serious and hes had some time to calm down and think, he'll come around. If that doesnt work, experiment with different punishments, maybe hes the kind of kid who learns best from extra chores or something else taken away or a swat on the butt. Make sure to back up every punishment with a talk about what he did, why its wrong, and what he should have done. Punishments really dont matter and wont have a long term effect if they dont understand why it is that they need to do what your telling them to do, if they understand then they are more likely to follow the rules because they know that they are the right things to do.