You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I need your assistance about modification of my reservation which I have done long back to travel in the next month to Chicago but all of sudden my schedule got postponed to some other as on of my relative got expired last night. Can you please help me about that?

ASSISTANT: Sure, I will help you in changing your existing reservation. I need to know your name to find the reservation in our database. So, please provide me your name to check the status of the reservation.

USER: Thank you for reacting positive about my request. I have done the reservation with my name itself that is Charles Thompson.

ASSISTANT: Charles, I will search in our existing records of reservation. I will get back to you with your reservation details. So, please wait for a minute.

USER: Ok, take your time and get back with the positive result about my reservation.

ASSISTANT: Charles, there is no reservation found with your details as you did not pay for the ticket.

USER: I have paid the fare in online itself and I am having the transaction of the fare. Kindly, recheck it.

ASSISTANT: We do have the details of the transaction and the problem lies with your bank. Kindly please check your account for refund amount.

USER: I have got conformation about my reservation with your service too. So, problem lies with your service.

ASSISTANT: Actually, we provide system generated receipts for our customers. We also sent mail regarding failure transaction. Kindly, check with your bank.

USER: Oh! ok, I will check with the bank it might be happen because of the insufficient amount in my account. Anyways thank you for your kind information.

ASSISTANT: Thank you for utilising our services, have a great day.

USER: You are welcome.