Refuse to continue with learned broadcast (4,3,4)
I believe the answer is:
draw the line
'refuse to continue' is the definition.
I can't judge whether this defines the answer.
'with learned broadcast' is the wordplay.
'broadcast' indicates anagramming the letters (letters scattered or cast around).
'with'+'learned'='withlearned'
'withlearned' with letters rearranged gives 'DRAW THE LINE'.
Can you help me to learn more?
(Other definitions for draw the line that I've seen before include "what an angler might do?" , "Find unacceptable - fix a limit" , "Set a limit on - reasonably object to" , "Set a limit on what's allowed" .)