Hello.
user
Hello.
assistant
Myself Matthew Brown.
user
How may I assist you today?
assistant
Due to some urgent client meeting, I am going to change my existing reservation. Can you please help me for this?
user
Sure, I am happy to help you with that.
assistant
Thank you.
user
Please wait for a while, I will get back to you.
assistant
Sure, I will wait for your response.
user
I am sorry to say that there is no reservation found under your details.
assistant
Not a big deal, anyway thank you very much for your service.
user
Thank you for contacting  us, have a safe journey.
assistant