body: Can a well-known, general, legal rule(s) of law overrule a claim made within a terms of service agreement that a customer has agreed to?
  
  
  Something along the lines of "the claim was rejected because they were not acting in good faith". Is there a name for this concept? 
  
  
  An example would be appreciated.
  
  
  
title: Can a general rule of law be used to reject a claim made within a signed service agreement?