Neighbours with children

I don't know what to do? I have lived at my flat for three years and although I am hypersensitive to noise (partly to do with my aspergers) and I have loved living here. In March 2015 I had a romanian family move with 2 children and from time to time they were ok but in October I have noticed the children getting loud (three year old and a baby) running around as there living room is in a conservatory and my entrance is concrete stairway. I understand there children and I do shift work and I am constantly tired. I went down there to speak with them but there english isn't great and they were like kids in bed at 8pm but most of the time it is 10pm. I tried speaking to the landlords about this who have written to them. Every time they run around it sets me on edge and I try and be sympathetic because there children and I don't have any savings to move at the moment well a bit but not enough to move yet. Any advice would be good