Guys,
There is now a new solution, ... Just tried it myself a few days ago,...
It works a treat, and i have finally managed to stop those abusive calls.
Its called
www.calltrap.co.uk
You can see the callers numbers ( even if they withold it!! ) and you have the option of automatically recording the calls too... ( in case you need evidance ).
If someone ( ex wife's new fella in my case) is prank or abusive calling you, you can now get them in some real trouble!
Hope that helps!
Sam.