answer: #Person2# calls Jenny that the mobile phone #Person2# bought from her has problems receiving calls since Tuesday. Jenny checks the mobile status and detects that the cause is the upgrading network.
documents: #Person1#: Dood morning. This is Jenny speaking, what can I do for you?
  #Person2#: Hi I am calling to complain about the mobile Phone I bought from you last Sunday. The model is Samsung Galaxy 3818. I cannot receive any incoming calls it always gives collars a busy signa. Do you know what the problem could be?
  #Person1#: Can you send any short messages?
  #Person2#: Yes, I can also call other People.
  #Person1#: Could you please tell me how long this has been happening?
  #Person2#: Since this Tuesday, the day before yesterday. You know initially I thought it was the mobile's problem, but then I realized it might be caused by the signal.
  #Person1#: Do you still have your receipt?
  #Person2#: I have it at home, but I don't have it with me at the moment.
  #Person1#: Could you please read the serial number of your mobile Phone to me?
  #Person2#: I can check whether there is a problem with the mobile Phone is self. The secret should begin with 08381.
  #Person1#: Just a minute. Let me see yes 08381823923.
  #Person2#: Sir I have check your mobile Phone status and everything is fine. I see a note here by our engineer. There are problems with receiving calls to to the upgrading of our network and it looks like your number could have been one of those affected. Our apologies for any inconvenience we've caused you.