Hello, I am David Walker.
Hello, how can I provide assistance to you today?
 I want your help in making some changes in my existing reservation due to the busy schedule on my previously planned dates. Can you help me in changing my reservation?
Sure, we are perky to help you.
Thank you.
Please wait for a while, to check the present status of your earlier reservation and let you know.
Sure, I will wait for your response.
Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.
Oh! I think it does not reserved properly.
Thank you for reaching us.
Thanks for your response.
Have a blissful day!.