Hello.
Hello. How can I assist you at this moment?
Due to some personal problems, I would like to change my existing reservation. Please help me out.
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 Patricia Moore.
Ok, please wait a moment.
Sure, take your time.
Sorry Patricia Moore, no reservation has found under your name to change.
Ok, no issues. Thank you for your information.
Thank you for choosing us, have a good day.