Mr.wang,
  I hope that your travel plans will bring you back to Shanghai in the near future, so that we may have the opportunity of taking care of you again and to show you that these regrettable events were not a true example of our usual high services and hospitality. In the meantime if I, or any of my team, can be of any further assistance to you please do not hesitate to contact me at your earliest possible convenience.
  Sincerely yours,