【正确答案】[范文] A Letter of Complaint Dear Sir or Madam, I am writing to lodge my complaint about the poor quality of an air conditioner that I purchased in Sun Appliance Store. Frankly speaking, your store has always been my favorite. On April 6, 2015, I bought an air conditioner (serial number 45927) from one of your chains located in Jinan. But seven days later, the fan began to make so much noise that I could not sleep well at night. What is worse, the cooling system didn't work well and the machine began to leak. I do hope that a repairman can be sent to my home without delay. I wonder if you could pinpoint the cause of the malfunction as soon as possible. By the way, if you can't, I am afraid that I will request a full refund or a new air conditioner. I would appreciate all your assistance concerning this matter. Look forward to your reply. Yours sincerely, Li Ming