I'm 17 I left my mums 4 years ago now due to the way my step dad treated me, I have 2 little sisters who still live there one 14 who has the same dad as me and one 9 who is my step dads, my mum using it as a weapon againist me makes it differcult for me to see them, I was a naughty teenager and troubled followed me, but since I've left I've sorted my head out and screwed on, I live indepently and want to be able to see my sisters without all of the hassle is there anyway I can get leagal visitings, I don't want to take them away from my mum, but see them weekly/fortnightly

I assume you are in the UK? Is that correct?

Yess

Someone from the UK will have to answer this,

I can speak from the perspective of if you was in the USA.

If you was in the USA you would have no legal rights because your parents have the responsibility to do what's in the best interest of the children... and its obvious they still see you as a bad influence and at worst a threat and the issues that resulted in you leaving haven't been resolved yet to their satisfaction.

From your opening sentence its clear you still don't see your part in the problem yet and still blame them for everything. Because at 13 you do what your parents tell you to do... not set the rules of the house yourself.

That is the real root of the problem. Because 4 years later you still blame them entirely.