We get the same pests here in Scotland. Fortuneately they use an international exchange and our phone company is now blocking all unwanted calls. They got crafty and started using skype as it came up with a 00000000000 number.

I had some fun with a couple of them before the calls dried up.

"Hello could I speak to Meester Veelson pleese"
" Why ? "
" Are you Meester Veelson ? "
" No I'm Dect Sergent George Bliss of the Inverness Royal constabulary. You have called the scene of a murder investigation. This is the 3rd or 4th time you've called recently
why do you wish to speak with the deceased ?
Silence......
I played a police siren wav through the pc speaker and then a phone ringing.
" Hello Why have you called this number again, how well did you know the deceased ? "
He tried to speak but could only stutter.
" We have traced your number and will be in touch soon. Please do not try & leave your country "
The guy hung up and never called again