Complaint when money box originally up-ended (4)
I believe the answer is:
beef
'complaint' is the definition.
(beef can mean a complaint or objection)
'money box originally up-ended' is the wordplay.
'money' becomes 'fee' ().
'originally' indicates taking the first letters.
'up-ended' says the letters should be written in reverse (in a down clue, letters go up).
The first letter of 'box' is 'b'.
'fee'+'b'='feeb'
'feeb' back-to-front is 'BEEF'.
'when' is the link.
(Other definitions for beef that I've seen before include "Meat of the cow" , "Grumble - muscle" , "Brawn; grumble" , "Grumble over cattle meat?" , "Small errand" .)