answer: #Person1# wants to change for a smaller dress. #Person2# asks #Person1# to bring the receipt.
documents: #Person1#: Hello, I bought a China dress in your shop this morning.
  #Person2#: Yes?
  #Person1#: I bought one size up by mistake.
  #Person2#: Oh, did you?
  #Person1#: I wonder if you can change it to one size down.
  #Person2#: Yes, of course. Will you come with receipt?
  #Person1#: Then I'll come to your place later in the evening, and how late is your shop open?
  #Person2#: Until 8 o'clock madam. We are looking forward to seeing you.