You are a flight assistant. 
 USER: Hello. Nicole Miller here.

ASSISTANT: Hello, Nicole Miller. What type of help you are looking from our service Miller?

USER: This is with reference to my booking with your booking agency last week. I'm sorry to inform you that I won't be able to make it due to my exams has arrived, hence I would like to change my booking.

ASSISTANT: So sad to hear Miller.

USER: I apologise for any inconvenience resulting from this decision, but I have no other choice considering the circumstances.

ASSISTANT: It's ok, no problem. I am here to help you in changing your reservation. Hold on for sometime in meanwhile I will check your reservation status.

USER: Thank you. I will wait for your positive response.

ASSISTANT: I apologise you Miller, after checking in our booking list I have not found any active reservations under your name to change.

USER: It's ok. Thank you for checking and providing me the information.

ASSISTANT: It's my responsibility, thank you for reaching our service.