【正确答案】Dear Sir or Madam,
I am writing this letter to you to express my deep regret that I got the wrong laptop with a brand unknown to me.
I have to say that your wrong delivery brought me great inconvenience and caused a great loss due to the fact that I planned to bring the laptop with me to Hong Kong tomorrow．The computer with the right brand is very important to me in the following days.
Please figure out an immediate solution to the problem and make proper compensations.
Looking forward to your reply!