Late yesterday evening, I received a call and an Email message from Elizabeth King of Amazon's "Executive Customer Relations Team." Elizabeth apologized and pointed out that bringing the gift card back was a simple trick and the customer service representative should have known how to do it. She went on to tell me that the magic trick had been done and that the gift card should work as expected now.
I appreciate Amazon's quick action, but do wonder about the design of their system. Why is it possible to apply a card, but not remove that application if there is an error? I guess that they don't often deal with fumble fingered analysts.