Refuse cold chop sent back for demanding chap (7)
I believe the answer is:
exactor
'demanding chap' is the definition.
(a demanding or exacting person)
'refuse cold chop sent back' is the wordplay.
'refuse' becomes 'rot'.
'cold' becomes 'c' (eg on taps).
'chop' becomes 'axe' (axing is a kind of chopping).
'sent back' says the letters should be written in reverse.
'rot'+'c'+'axe'='rotcaxe'
'rotcaxe' written backwards gives 'EXACTOR'.
'for' is the link.
(Other definitions for exactor that I've seen before include "One forcing payment" , "Demanding person" , "Blackmailer" , "One demands" , "demanding type" .)