Hi, How can I help you today?
I've been trying to buy something, but it keeps saying my credit card is invalid.
I see, just a moment please Did you try to re enter the information?
I tried several times.
I see, have you tried logging out then in of the account?

Are you there?
Yes, I have tried logging out.
Ah, it did not do anything?
No, it still says my card is invalid.
I see, have you checked the expiration date on the card?  It might be too old.
No, I haven't checked that. I'll look and see. Yes, it was expired. I'm sorry - I'll use a different card.
Ah ha! There we go. Is there anything else I can help you with today?
No, that was all!
Great, we appreciate your business at AcmeCorp and have a good day!