Bachelor reversing charge causes complaint (4)
I believe the answer is:
beef
'complaint' is the definition.
(I've seen this before)
'bachelor reversing charge' is the wordplay.
'bachelor' becomes 'b' (abbreviation e.g. BA=Bachelor of Arts).
'reversing' is a reversal indicator.
'charge' becomes 'fee' (fee is a kind of charge).
'fee' back-to-front is 'eef'.
'b'+'eef'='BEEF'
'causes' is the link.
(Other definitions for beef that I've seen before include "See 24" , "Grumble over cattle meat?" , "Meat - complaint" , "nickname of US State" , "joint, perhaps" .)