Cat stuck on roof on mannock road! He's been stuck there for more than 24 hours

There's a cat stuck on the roof of a house on mannock road, he's been there for over 24 hours with no food or water and I'm worried about him in this heat. I've tried contacting the RSPCA but they refuse to send help as it doesn't meet their criteria. I'm in contact with the people who live in the adjoining house but there's not much we can do on our own. Does anyone have any ideas? Is there anyone who can help? The cat's stopped walking around and he looks really miserable.