For goodness sake! Either don't answer (caller ID etc) or, if you do and suddenly realise it's CC - just say 'Hello' followed (on tape) by 'It's really annoying when the line goes dead like that!' Meanwhile, the plaintive and increasingly desperate voice at the other end is saying 'Can I speak to Captain ( or should it be 'Mister') xxxxxx - it's Cathay Pacific Crew Control.'
When/if they call back - don't answer at all. Simple really.
They should NOT call on a G day and would stop if nobody answered.
So - like many things in life - you reap what you ( or some anyway) sow.