...service and structured care, making a killing (8)
I believe the answer is:
massacre
'a killing' is the definition.
(massacre is a kind of killing)
'service and structured care' is the wordplay.
'service' becomes 'mass' (I've seen this in other clues).
'and' says to put letters next to each other.
'structured' is an anagram indicator.
'care' is an anagram of 'acre'.
'mass'+'acre'='MASSACRE'
'making' is the link.
(Other definitions for massacre that I've seen before include "Carnage" , "Slaughter, pogrom" , "Destroy" , "Overwhelming defeat" , "Heavily defeat" .)