Read law about unfair treatment (3,4)
I believe the answer is:
raw deal
'unfair treatment' is the definition.
(I've seen this before)
'read law about' is the wordplay.
'about' indicates anagramming the letters.
'read'+'law'='readlaw'
'readlaw' with letters rearranged gives 'RAW DEAL'.
(Other definitions for raw deal that I've seen before include "Inequitable treatment" , "Untreated wood" , "Unjust payoff" , "'Harsh, unfair treatment (3,4)'" , "cruel treatment" .)