Hit toy, toy I mistreated, being snobbish (5-5)
I believe the answer is:
hoity-toity
'snobbish' is the definition.
(thesaurus)
'hit toy toy i mistreated' is the wordplay.
'mistreated' indicates anagramming the letters.
'hit'+'toy'+'toy'+'i'='hittoytoyi'
'hittoytoyi' with letters rearranged gives 'HOITY-TOITY'.
'being' is the link.
(Other definitions for hoity-toity that I've seen before include "Affectedly genteel" , "Stuck-up, snobbish" , "Haughty" , "Stuck up" .)