Christopher won't do his homework?

So I have a son named Christopher who is 12 and keeps procrastinating. I have tried everything, from grounding to stop him from talking to friends and if I do any of that stuff, he just cusses me out and I'm sick of it. He calls me an asshole and a *****. I tell him you are almost in eight grade, you need to start acting like a young man and he just says I am not a young man yet and who gives you the right to make me grow up. The bottom line is I need serious help. What should I do?