Hi.
Hello. How may I help you out?
I want to change my reservation as I have to prepare for my exam, could you please do that for me?
Sure, I will help you in changing  the reservation.
Thank you.
Please wait for a while.
Sure.
May I know your name please?
My name is Melissa Thompson.
Sorry, there are no reservations found in our database.
Not an issue, anyway thank you for checking.
Thank you for choosing us.