Charlie with previous request to make unsolicited visit (4-4)
I believe the answer is:
cold call
'unsolicited visit' is the definition.
'cold call' can be an answer for 'visit' (I have seen 'Unannounced visit' mean 'cold call' so perhaps 'visit' could also mean 'cold call'). I'm not sure about the 'unsolicited' bit.
'charlie with previous request' is the wordplay.
'charlie' becomes 'C' (phonetic alphabet: alpha, bravo, charlie etc.).
'with' means one lot of letters go next to another.
'previous' becomes 'old' (I've seen this in another clue).
'request' becomes 'call' (call is a kind of request).
'c'+'old'+'call'='COLD-CALL'
'to make' is the link.
Can you help me to learn more?
(Other definitions for cold call that I've seen before include "ring, unexpectedly" , "Unannounced visit" , "sales pitch" , "make uninvited visits" , "what salespeople can do" .)