On new arrivals

There's a Polish girl in my school who recently approached me asking for help preparing for her exams. I accepted willingly, cause God knows I needed something good, ie. to work with a kid who actually cares. But this is not good. She is hard working and puts every effort in, but her English is just not good enough. And what I don't understand is how could a child be schooled in the UK for almost two years and still not speak any English? From what I gathered, she had initially refused to learn English, a rebellions teenager angry about having to moved into a foreign country and into a school where her and her brother are constantly bullied. But how come no one ever cared enough to talk her out of it? Why nobody cared to check how long she's really been here before denying her the right to a dictionary and extra time in exams? And actually, how come kids have that right only for two years after their arrival regardless of their level of English?
She has special provision. A translator for two lessons a week. How is she supposed to cope? Why no one asked me earlier if I would be willing to help?
And, in the first place, what is the point in putting new arrivals straight into mainstream schools? I knew a girl who was put straight into year 11 and forced to take her GCSE's while all she could say in English was 'hello'.
From what I've heard, there used to be special centres for new arrivals, where they were schooled for up to a year learning English only. I wonder who decided it was a bad idea. I wonder how the current way of doing things could possibly be seen as better.
It just makes me so angry - all those kids arriving here and so absolutely failed by the education system. What are their chances to succeed? None, unless of course their parents are wealthy enough to provide them with private tutoring.