【正确答案】Dear Sir or Madam,
I am writing to complain about the Nokia mobile phone I bought in your store last week when I was on business in Beijing. At first it worked perfectly. But several days after I came back home, it can not send short messages and take photos. I'm pretty sure I used it properly. Two days ago, I called your store and discussed it with the assistant. The result is quite dissatisfactory.
I write to you in hopes that you may find a good solution for me. My concern is either you may have the mobile phone replaced or you may give me a full refund. Your prompt attention to my letter would be highly appreciated.
Yours Truly
Zhang Ping