Assistance rebuffed, keep record of reported conversation (8)
I believe the answer is:
dialogue
'reported conversation' is the definition.
'dialogue' can be an answer for 'conversation' (dialogue is a kind of conversation). I am unsure of the 'reported' bit.
'assistance rebuffed keep record' is the wordplay.
'assistance' becomes 'aid' (synonyms).
'rebuffed' says the letters should be written in reverse.
'keep record' becomes 'logue' (I can't explain this - if you can you should give a lot more credence to this answer).
'aid' in reverse letter order is 'dia'.
'dia'+'logue'='DIALOGUE'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for dialogue that I've seen before include "Talks" , "Conversation as in a play" , "Lines spoken in films, books etc" , "The words spoken by characters in a play" , "The speech in a play" .)