Question Author
Thanks everyone, sorry for being a bit touchy. Anyhoo, the door was shut, they just didn't lock it as their Mum was in and up and about. I have contacted the police but they said that because there has been no forceable entry that there is nothing that they can do, I find this absolutely ridiculous. They said that they would send me the usual "Dear Victim" letter and gave me a crime number. We only moved in this house 3 weeks ago, fortunately I stayed with the same insurance company, but it all sounds so dodgy, even to me. All I can do is try and make a claim I suppose, it's a sad day when you have to keep yourselves locked in your home.
Thanks again everyone, love to you all x