Just advice, even the user it self cannot accepted the case or solved. You must somehow educate the support live chats to respond based on the latest investigation or progress about the case. Not ignore the chats from the user it self, you can repeated the investigation answer to the user to avoiding some situation you're ignore the chats. Mostly, If the user are getting the same reponse or situation they don't like.. they will opened on some website review like (CG/AskGambler) you can response to there as well to defend your invetigation and how the third parties seeing the case. If they favor to you, should be fine.