answer: #Person1# is calling to inquire about a missing bill. Then #Person2# tells #Person1# to contact the post office and send #Person2# the proof of their mistake.
documents: #Person1#: I'm calling today about a bill that I never received.
  #Person2#: Can you tell me which credit card it was for?
  #Person1#: It was for my Master Card.
  #Person2#: You should've gotten that bill two weeks ago.
  #Person1#: I haven't got it in the mail yet.
  #Person2#: The computer is showing that all bills have been mailed.
  #Person1#: What am I supposed to do about my bill then?
  #Person2#: Maybe you should call your post office.
  #Person1#: But if it's their mistake, can I get an extension on my bill payment?
  #Person2#: Yes, but you will need to send us proof of their mistake.
  #Person1#: Okay, thank you very much for your help.
  #Person2#: Not a problem. Enjoy the rest of your day.