Disgusting refusal is nothing to this person (7)
I believe the answer is:
noisome
'disgusting' is the definition.
(thesaurus)
'refusal is nothing to this person' is the wordplay.
'refusal' becomes 'no'.
'nothing' becomes 'o' (looks like zero - 0).
'to this person' becomes 'me' (I've seen this in other clues).
'no'+'is'+'o'+'me'='NOISOME'
(Other definitions for noisome that I've seen before include "Foul-smelling - semi-Ono (anag)" , "Offensively smelly" , "Evil-smelling - sounds loud" , "Extremely unpleasant" , "terribly unpleasant" .)