Behavioral Problems

I need some advice and tips on how to help my child.. my son is 3 years old and is constantly disrespectful and hateful 24/7. He tells me he can do what he wants to do, smacks me, screams at me, hits the walls, spits, he does it all. His dad and I have tried and tried to explain that we don’t treat people this way, and that it’s not nice and he’ll say sorry and do it again 5 minutes later. We’ve used time out and even putting soap in his mouth when he says certain things. Nothing is helping. Please help!!!