Hello.
user
Hello. How can I help you?
assistant
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?
user
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.
assistant
It's ok.
user
Would you like to travel on any other dates?
assistant
No, thank you for the  information.
user
Thank you, have a good day.
assistant