extort vs refund

extort

verb
  • To obtain by means of the offense of extortion. 

  • To take or seize from an unwilling person by physical force, menace, duress, torture, or any undue or illegal exercise of power or ingenuity. 

  • To twist outwards. 

refund

verb
  • To return (money) to (someone); to reimburse. 

noun
  • An amount of money returned. 

How often have the words extort and refund occurred in a corpus of books? (source: Google Ngram Viewer )