Hi. Janet Baker here.
user
Hello, how may I  assist you today?
assistant
Due to my health problem I want to change my reservation, can you please help me to change my reservation?
user
Janet Baker, please wait for a moment t check with your reservation.
assistant
Ok.
user
Sorry to inform you, there is no reservation found by your name.
assistant
That's ok, thank you for you help.
user
Thank you for choosing us, have a great day.
assistant