I wonder if she feeds off you OP, like dusters says, she's a bit of a drama queen
Right now, you are fixed firmly in her mind as 'bad cop'. Stop reacting. I know that is easier said than done, but stay neutral.
My DD, at sixteen, had an abusive boyfriend, and in turn, he tried to abuse me. I think DD picked a bad boy because her father and I were at the end of our marriage, he had emotionally checked out, she thought I was a soft touch, and would tolerate her rudeness and his treatment of her.
This was not at the same level as you are suffering, but it was bad enough.
Initially, I played into their hands, I came down hard on them. She became worse, he encouraged her. Then I said I didn't want him in the house (found an empty packet which reeked of pot in the garden, where they had been). This drove them closer, and she started to stay with him at his mum's house. She was incredibly angry and hostile to me.
So I just stopped. Never asked her about him, never mentioned him. This intrigued her, she'd instigate conversations about him, and I'd just say 'oh yes' or 'oh right'. She'd leave her room a tip, and I knew he'd been in the house, she'd leave a sweatshirt or something of his laying around to provoke me. I ignored it all.
After a month or two, he lost his appeal. I think she realised that he wasn't as cool as she thought. Certainly I think she quite enjoyed winding me up, and when she failed to, it all got a bit boring.
She dumped him a few months later, and returned to her lovely self. Five years later she has a lovely boyfriend.
I don't know if this helps, I know it's horrible to sit back and do nothing, but it helped me.
Good luck.