Just an update to a previous outstanding issue: King Soopers replaced the Amazon gift card in full and I have confirmed that it works. I hope that they got their money back from Amazon. Unfortunately, while the incident has soured me a little on Amazon (what with their lack of help or information), they still have decent selection and prices and I will probably continue to shop with them. I might be a little more open to alternatives.
Other than the fact that no one ever called me back from King Soopers to let me know to stop by and pick up a new gift card, I can't complain about their service on the issue at all.
Now, I'm just wondering how a physical gift card that I have in my possession doesn't exist. Maybe time travel does exist. I'll try again in a year.