I'm relieved to hear the amazon backend is temporary. I've had lots of trouble trying to place an order and gave up trying. I was worried you guys were bought out!
We do some ecommerce where I work and we had a similar scenario a few years ago. The lesson we learned was "host your own store". We licensed the web storefront and had rights to modify the source and run it on our own hardware. We also have a perpetual license for our order fulfillment software. No more surprises!