Hi Rosie,
I understand completely how you feel, I had this not so long ago - rented tennants with screaming, unruly, noisey kids. It was hell to live next door to - the parents were just as bad, swearing at their kids and shouting, for a year i could not sit in my own back garden due to the noise, but they have since been evicted now and my life is peaceful once more, I was lucky, but i did in the beginning try and have a work with them about the noise in a pleasant manner and all i received was abuse in return. I wish you all the luck, indeed put up a high fence, make sure you get permission though and I hope it all sorts itself out, my thoughts are with you no this one.
RQ x