Send back refusal, with note reflecting party's official line (9)

'reflecting party's official line' is the definition.
I can't tell whether this defines the answer.

'send back refusal with note' is the wordplay.
'send back' says the letters should be written in reverse.
'refusal' becomes 'no' (saying no to something).
'with' is a charade indicator (letters next to each other).
'note' becomes 'message' (a note is a short message).
'no' written backwards gives 'on'.
'on'+'message'='ONMESSAGE'

Can you help me to learn more?