Hi, Dennis Mitchell here.
Hello, how can I render you?
 I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation. Can you help me?
Sure, that's what I am here. Please wait for a while, I check the reservation list and revert to you.
Sure, I will wait.
Thanks for being waiting. Unfortunately, there is no reservation found on your name.
Ok, it's not a problem. Thanks for your response.
Thanks for approaching us. Have a happy day.