[Q] Did my daughter ruin my HDX7? topic

A week ago, my 2 year old daughter was using my HDX7 under her profile. It was set up using Amazon protocol and she did not have administrator access. When my wife looked a few minutes later, she saw a gray Kindle Fire logo and the word 'erasing'. It was stuck in that mode for about 2.5-3 hours. Finally, my wife called Amazon 'tech support' who gave her a bunch of instructions about holding down the power button and volume button. She followed their instructions, and a gray logo appeared with the word '[fastboot]' on the screen. It has been like that ever since. Upon numerous calls to Amazon, they have accused us of rooting the Kindle. It has never been rooted before. No one in our family knows how to do this. Also, this just happened 35 days after the warranty. There seems to be nothing Amazon can do. Apparently, I can't even send it in to Amazon for them to repair. They claim they don't fix them (even though they sell refurbished ones).
I have tried following numerous forums with failure. ADB gives me a 'device not found' error and any other attempts have said, 'flashing not allowed on hw." I would be happy just to have it working again. If anyone knows how to fix this, it would be greatly appreciated.