Sadly the recordings cannot be used in courts (I know you cant over here) due to it was illegally obtained.
But glad stuff is being done, we have had several of these calls in the past, my father not being tech savvy and security aware almost fell for it.
Luckily I was walking by when I heard the phone call, I asked who it was and my father said BT, so I grabbed the phone and spoke to them and they said that (blah blah blah IP Address blah blah) I told them where to go and hung up.
See BT have been instructed to never phone the land line and to contact me on my mobile.
So I have told any phone calls stating they are BT to tell them to call the FPOC (First Point of Contact) and then hang up.
I did ask my father if they asked him to install stuff, he said no, but I redid his PC anyhow.
Paul