100 to get banal shout for unwanted sales patter (4,4)
I believe the answer is:
cold call
'unwanted sales patter' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'100 to get banal shout' is the wordplay.
'100' becomes 'C' (Roman numeral).
'to get' is a charade indicator (letters next to each other).
'banal' becomes 'old' (I've seen this in another clue).
'shout' becomes 'call' (synonyms).
'c'+'old'+'call'='COLD-CALL'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for cold call that I've seen before include "Make unsolicited contact to sell something" , "Sales technique" , "make uninvited visits" , "what salespeople can do" , "Unannounced visit" .)