Partial solution
New answerphone - on my old answerphone I had recorded my own greeting. This mostly resulted in the scum leaving some sort of message.
On the new machine (can I say Panasonic) there is a pre-recorded greeting by a nice sounding and apparently very well known young lady. Most of the sh1tbags seem to know it and rarely get beyond her first few words before hanging up.
Of course, anything not recognised on the caller display is left for my electronic ladyfriend to deal with.