How can Ford KA engine rattle be fixed after broken spark plug? ?

...im going by what the garage told me, they said cos spark plug broke the ceramic bit would have fallen straight away into engine and has caused engine damage, hence to tapping sound when engine running. I have paid them to fix this but i think they are telling me lies. Other pple have told me this is rubbish. Thanks for your answer Wickham, I appreciate you responding

Susan
June 2010

when you say it fell through does that mean into the combustion chamber?If this was not removed get the head off pronto before any more damage is done

wickham
June 2010