I'm a single mom with a kid who was really defiant, too. What I found (through the help of a number of people) was that I had to set the boundaries and be ultra consistent.
When he says he doesn't care and he hates me, it's because he really care and he's afraid that if he says he loves me, he'll get hurt with the response.
He earns an allowance each month (maximum $12/month). However, if he swears or calls me the B word, I subtract $0.25 each time. At the end of the month, he gets a sheet that shows what he earned and then total amounts subtracted for language, not doing chores, etc, categorized by type. Also, when he swears, I remind him that the money is being taken away.
The other thing I've found with him is that the defiance is totally fear based. Over the last 7 months he's gone fro ultra defiant to almost no defiance because we've been able to address fears. When he gets defiant and rude, he has to take a 10 minute break to calm down. If he won't go to his room, I just refuse to respond him for 10 minutes (and that is SO hard). The quiet helps him calm down. After that, he's able to say, "I'm upset because...." Then I ask leading questions or yes/no questions to draw out the problem in detail and to pinpoint the fear and we talk it through. One thing, though, is that I have to watch my posture when talking through with him. If he's sitting on the floor, I need to sit on the floor for the conversation; if he's sitting on the couch, I sit on the couch or floor; if he's standing, I'll sit. The reason for sitting is because since I'm bigger than him (not by much since he's 12 and I'm short), it feels like intimidation to him for me to be physically taller than him. So if I get low and even or lower, he feels like he is safer to talk.
I recommend the philosophies of 2 organizations: Love and Logic Institute (www.loveandlogic.com) and The Beyond Consequences Institute (www.beyondconsequences.com). Beyond Consequences first book "Beyond Consequences, Love, and Logic" helped immensely.