Hello.
Hello. How can I assist you at  this moment?
Can you help me to change my existing reservation?
Sure, I am happy to help you with that.
Thank you.
Can I  have your good name please to check your reservation status?
My name is Susan Evans.
Ok, please wait a moment.
Sure.
Sorry Susan Evans, no reservation has found under your name to change.
No problem, thank you for the information.
Thank you for choosing us, have a good day.