My boss's mobile just rang, while she's on the office land line, so I answered it for her...
I got a phone ringing tone, then this conversation followed:
Him: Hi i'm _____ how are u?
Me: Good thanks
Him: The reason for my call is to see if you're happy with your mobile service
Me: The owner of the phone is busy at the moment, can you call back another time?
Him: What are they doing?
Who on earth ask that!
Me: They're on another call
Him: Can you get them off the phone, this is very important
Me: No.
Him: Why not?
Me: They're busy.
Him: Well it doesnt matter, it can be for your mobile service too, are you happy with your mobile service?
Me: Yes thank you.
Him: <Company name> Can offer you a better deal.
Me: No thank you.
Him: Why not?
Me: No thank you.
Him: Why not?
-hangs up-
the "What are they doing", "Get them off the phone" and "why not", i found extremely rude for a cold caller... geez man!