come again vs get back

come again

intj
  • Used as a polite farewell to a visitor, inviting a return visit. 

  • A polite formula used when one has not heard or understood what has been said, or to indicate surprise. 

get back

verb
  • Return to where one came from. 

  • To retrieve, to have an item returned. 

  • To do something to hurt or harm someone who has hurt or harmed one; to take revenge. 

How often have the words come again and get back occurred in a corpus of books? (source: Google Ngram Viewer )