Nov. 16, 2020
 Dear sir or madam,     
        I am writing this letter to______（投诉）the quality of the phone I bought last Tuesday in No. 1 Department store. The phone always______（黑屏）. I called the ______(售后)， but the problem was not solved. Therefore, I have sent back the phone and the receipt to you and strongly insist that you ______(退回我) 5000 Yuan as soon as possible.
      I would be ______ if you could have this matter settled.
Yours sincerely,
Tim Smit