Hi, Gary Thompson here.
Hello, how can I assist you today?
Due to some health issues, I want to change my existing reservation. Can you please help me with this?
Sure, we are here to help you for that. Please hold on.
Sure.
Thanks for being hold, we did not find any  reservation on your name.
Ok, not an issue. Thanks for your assistance.
Thank you for choosing us. Have a nice day.