Hello.
Hello. How can I help you?
Thomas Thomas here. I want to alter my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your some time for helping me?
Sure, please give me a minute so that I can check with your previous reservation details. Sorry, there is no reservation found with your name.
It's ok.
Would you like to travel on any other dates?
No, thank you for the  information.
Thank you, have a good day.