I remeber a Salesman cold calling m eon the phone. It was from a number you couldn't trace.

I asked him who the hell he was and that my number was ex directory, so how come he got to phone me.

He said you don't know who I am

I said No

He said "F*ck off" and the line went dead.

Couldn't trace the number.

However that was true.

Makes me laugh now, but not at the time.