How hard would it be to take on a 'county council' ?

Basically,just before xmas last year i went to collect my 4yr old son from nursery school.When i arrived i was told by one of the workers there that he had a accident and had a small cut on his head,when i actually went into the room where he was,he was sat in a chair looking dazed and had blood running down his face coming from a gash on his forehead.None of the workers knew how he had done it all they could tell me was that my son had gone up to a member of staff and said that he had slipped and hit his head on a rock.The gash was pretty deep but yet all they had done was wiped it with a wet cloth,i was not offered a lift to the hospital or doctors either all they said was that i may need to take him to the doctors and get it stitched! I had to carry him home as he was too dizzy to walk and then took him to hospital to have it glued.I have started legal proceedings against them but have been told that its not actually the nursery i am taking on it is the local council.What do u think my chances are of being successful against them?