Person responsible for wrecking our cart (7)
I believe the answer is:
curator
'person' is the definition.
(curator is a kind of person)
'wrecking our cart' is the wordplay.
'wrecking' is an anagram indicator (I've seen this in other clues).
'our'+'cart'='ourcart'
'ourcart' is an anagram of 'CURATOR'.
'responsible for' is the link.
(Other definitions for curator that I've seen before include "Custodian of a collection" , "Museum keeper" , "Artistic director" , "Museum officer" , "Cultural employee" .)