answer: #Person1# thinks #Person2# has bought another handset but #Person2# just changed a case for it.
documents: #Person1#: Have you bought another handset
  #Person2#: No, it is the original one.
  #Person1#: This is silver gray, while I remember your handset was black.
  #Person2#: I have changed a case for it.
  #Person1#: Can a handset case be changed?
  #Person2#: Of course. That's why I bought this type. I can change its case frequently, so it is novel to use it.
  #Person1#: How many cases are accessible?
  #Person2#: There are two more, one is orange and the other is pink. I have bought them all.
  #Person1#: It's really going to be fresh all the time.