Abusive Relationship

I'm really worried about my cousin, she's with a guy who's really controlling and manipulative. She met him 2 years ago and since then he's just ground her down mentally so that she does whatever he tells her to do. It's gotten to the point where he's done crazy things like dragging her by her hair down the street, biting her face and even locking her in the boot of his car and then driving off.
She says she's too scared to leave him because he said he'd kill her if she did (I wouldn't put it past him to do something truly awful) so she just stays with him because she convinces herself he will change and that she loves him. Whenever I go to visit her he calls her every 5 minutes, literally the phone is constantly ringing and she always looks sad.
I'm determined to help her because only 2 years ago she got her life back on track, quit hanging out with the wrong people and got onto a training course to do the job she loves, only when she left her old friends she met him and if anything it's worse now than it was before. I'm going to speak to her about it properly, I'm sure there's some sort of police protection she can have to stop him coming near her. She lets him in her house because if she doesn't he just stands there and bangs on the door until she lets him in.
It's horrible to think of her being so scared and I can't just sit back and watch her become more controlled by him, the longer it goes on the worse things he may do. But I was thinking if the worse comes to the worse she will have to move somewhere else and change her phone number and everything. He even has her PIN number for her bank account.
I'm not sure where to start with helping her, what's the first step I should take because I don't want to do anything to make the guy angry so he takes it out on my cousin.

I only read half of the post but I have to say:
Get her or a family member to report it to the police. They can keep him away from her so he can't 'kill' her or anything..

Simple, they should break up. Tell her to do it on the phone and have her stay with close friends and family (yourself, for instance) and if he becomes angry then report him to the police. He only has himself to blame ;)

This isn't a relationship tied with love at all; she needs to get out fast. The police will have to protect people just like your cousin on a daily basis, so get them involved ASAP!!

After reading this all, I'd have to say to immediately get the police involved in this, because if she stays with him, it will just get worse, and she could be coming home with bruises just cause of him, you never know.

I hope your cousin will be okay.

Get the police involved is what i'd do.
She obviously deserves better than him, the police could give him a restraining order (I think it is...) if the situation is serious.

Hope it all turns out well!

Breaking up with him cannot be considered a solution. That guy sounds crazy. If there's no action taken, he might kill her. Sorry but it's the truth. Bring your cousin with you and your family members to the police station. Find someone to protect you both so that he won't do anything stupid on you both. Report it to the police immediately and if she still has the bite marks, scars of him beating her or whatever bruises of recent attacks, show it to the police and sue him for it. If she thinks that ******* will change for her, nah. Tell her to give up on him. It's very urgent and you have to do it immediately. Don't let that guy know what you both doing. Don't make him angry first or whatever you done might come to a halt.

Some of you really have no idea lol. Theres charities set up to counsel and help people like your cousin, do a bit of Googling for domestic abuse charities, call them, its what they are there for and theyll be able to give you the best course of action because some of what the people in this thread have said is crazy and will just m ake the problem worse and even make him obsessive. Call the charities, they have trained advisors to help with this kinda stuff, its an everyday occurence for them and theyll be able to direct her in the right way, they can consel and I think some will even provide lawyers and help to keep your cousin protected. The people that have said 'break up', bluntly, its not that easy. Domestic abuse is a mind game and can really do ****** up things to the victims mind, like making them feel dependant on the abuser, or like in this case, make them feel mentally incompetent and feel like it will all change soon.

I hope it gets sorted Chantelle, I know its not a nice thing. If I get a chance Ill post some links to the charities here.

Heres one http://refuge.org.uk/

I can see how frustrating it is for you but there is only one person who can sort this and it is your cousin. You can advise I guess but by taking direct action could mean that she falls out with you too. Sounds like she has low self esteem which is something you could help her with so she is strong enough to take action. :)

Thanks for the help guys, I really appreciate the responses, it's nice to have people's advice and support when you have to do something that's a bit scary.

@ Myke thank you for the link to the charity, I'm going to phone them today.

It's nice that you're trying to help your cousin, especially when the situation is as such. Hope everything turns out alright Chantelle.