You appear to have gone down the correct route with mediation and through your local authority. If that isn't working for you now, you should go in to see the officer who is in charge of the mediation and tell them it is not working. i son't think there is anything else to do, but go with the attitude that you really don't believe it is working, from what you write, and from your response tonight, I assume the council have pretty much supported everyone involved but this is breaking down isn;t it?