Keep complaining to the central manager (3)
I believe the answer is:
nag
'keep complaining to' is the definition.
I can't judge whether this defines the answer.
'central manager' is the wordplay.
'central' says to take the centre.
The middle letters of 'manager' are 'NAG'.
'the' is the link.
Can you help me to learn more?
(Other definitions for nag that I've seen before include "Badger continually like old horse" , "Annoy the old horse persistently" , "Be persistently painful" , "Old or over-worked horse" , "old trout?" .)