Martin Smith is a patient who always disrupts the clinic. He constantly complains about everything from the moment he enters until the moment he leaves. Karen is at the desk when he arrives to check out and pay his bill. When she tells him that he has a previous balance from a claim that his insurance did not pay, he argues that Karen filed the claim incorrectly. Karen is not in charge of filing insurance claims and did not handle any part of the claim in question. How can she be courteous to this patient?