Hello, Sandra Taylor here.
user
Hello, how may I aid you?
assistant
  The unexpected injury, the travelling authorities told that you are unfit to travel in flight with a suggestion of physician, so, I need to cancel my booking.
user
Sure Sandra. I will help you with that. Thanks for your patience, I have checked and there was no reservation found.
assistant
Ok, thank you for checking.
user
Thank you.
assistant