This is a good point and one I generally ascribe to, it's rarely going to be the chief/architect scumbag that's calling you.
I accept that they are often just people trying to earn a living and as much as I would like to scream and shout at the cold caller I don't. I am nearly always polite, asking them to not call me again and politely telling them I am hanging up.
However, one caller who was trying to get me to upgrade my mobile started going through his talk so I asked him to stop and politely explained that generally chose a phone in a shop and then call my provider to arrange an upgrade. The Cold Caller's reply to his was:
Caller: 'Arse!'
Me: 'Excuse me?'
Caller: 'ARSE!'
Me: 'That's not very nice.'
Caller: 'Penis!'
Me: 'I'd like to speak with your manager please'
Caller: 'Penis!'
Me: 'I have your number and you record your calls.'
Caller:
Hangs up
I then call the number back and asks to speak with the call centre manager, to whom I asked if they routinely record the calls and then I explain the preceding conversation. The manager says I will be receiving no more calls and the caller will be sacked. I had no more calls from that company so I can only assume the caller was also sacked.