Hello.
user
Hello. How may I guide you?
assistant
I am planning to change an existing reservation, due to health issue. Can you please change my reservation?
user
Sure, I will help you with the ticket changing process. Can I know on which name you have reserved your past ticket?
assistant
My name is Christine Brown.
user
Ok, please give me a minute. I will check the ticket status and get back to you.
assistant
Sure, I will wait for your reply.
user
I have checked in the confirmation chart list  but I have not found your reservation in that. Sorry for the inconvenience.
assistant
That's fine, thank you for your service.
user
My pleasure. Thank you for approaching us.
assistant