Hello. I am Timothy Roberts.
Hello. How may I guide you today?
I am planning to change an existing  reservation, due to health issue. Can you please change my reservation?
Sure, I will help you with that. Please wait for a while.
Sure, take your own time.
I am sorry to say that there is no reservation found.
That's ok. Anyways, thank you for your help.
Thank you for contacting us.