When I get call from numbers I don't recognise, I often respond with.
This is Captian Walter Walker, duty officer , Royal Navy Strategic Launch Control,
Please may I have your security code and preliminary target data.
If the caller persists I ask thme how they got the number etc, and tell them that they heed to be more careful, The UK is on high alert and they could've started a nuclear war by calling this number. Etc etc.
I've got a few variations.. another is Exeter hospital ear nose and throat department.
I've another one for the people who ring about my recent accident.. my head was torn off and the hospital stitched it on back to front.. surely I have a claim for negligence.
Often I string them along for as long as possible, give them loads of nonsense information, then when I get bored I tell them that I don't have a Sky account, and admit that I have been lying to them. At that point the call ends abruptly, or I learn a whole load of new things about my parentage.