Hello,.
Hello. How can I assist you?
Actually I have planned to attend the client meeting but due to some technical issues the meeting has been postponed. So, I want change my reservation, can you help me?
Sure, may I know your good name?
I am Joseph Walker.
 Ok, please wait I will revert  you in  a moment.
Sure.
Thank you for waiting. Sorry to inform you that no reservation was found on your name provided.
Ok, thanks for providing information.
 Thank you for consulting us.