Instead of proposed refund it swapped bad apples (9,5)
I believe the answer is:
forbidden fruit
'instead of proposed refund it swapped bad apples' is the definition.
I can't judge whether this definition defines the answer.
'instead of proposed refund it swapped bad' is the wordplay.
'instead of' becomes 'for' (I've seen this in other clues).
'proposed' becomes 'bid' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'swapped' says to put letters next to each other.
'bad' indicates anagramming the letters.
'refund' put after 'it' is 'itrefund'.
'itrefund' with letters rearranged gives 'denfruit'.
'for'+'bid'+'denfruit'='FORBIDDEN FRUIT'
Can you help me to learn more?
(Other definitions for forbidden fruit that I've seen before include "Illicit pleasure" , "Apple" , "Something naughty not allowed" , "Restricted as to diet?" .)