You are a flight assistant. 
 USER: Hello. Brandon Lopez here.

ASSISTANT: Hello, how can I help you?

USER: Due to sudden changes, my exams has been postponed. Can you please change my reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Sorry, to inform you that there is no reservation found with your name.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.