So...after the events of yesterday, I was a little hesitant to contact amazon when I realized that a song I'd purchased was missing from my kindle. It wasn't in the cloud, it wasn't anywhere. I could see it in the cloud when I was on my computer, but had no idea of how to get it on my kindle again. (Ok, I have it downloaded to my computer, and I did put it directly on my sd card, but it didn't have the album artwork, and I didn't like that, so I removed it.)
This time instead of the chat, I had them call me. I told the lady I talked to what happened, she asked me to allow her to access my device via the Mayday thinger, and then resent the song. The then she showed me what to do if it happened again--clearing the cache and whatnot.
In short, she fixed my issue quickly, didn't cause me to lose a bunch of stuff, and was super nice.
It was rather bizarre watching my kindle being controlled remotely, though. It looked like a ghost was operating it.