This is my #1 concern as well; the same has happened to me twice in 3 months. It's led me to a better understanding of Amazon's business, but without any real solution.
I do Amazon FBA, but I don't "sell on Amazon" and pay them a commission (even though that's the easy way to describe it). Amazon sources products from me for 15% (plus fees) less than I'm selling it to them. Amazon owns the customer. Amazon owns the advertising. Amazon owns the data. Amazon decides what will and won't sell and when. Amazon then owns the transaction. All I get is a tiny line and a small logo on a somewhat hidden page crediting me as a source. Hell, I can't even direct anyone to find more information about me.
If anyone has been in I.T. for long, you're aware of the incredible accomplishment that is Amazon's cloud services. What they've put together has to be one of the greatest technological accomplishments on the whole. Can you imagine what kind of decisions they can make with the marketplace data they have? They can recognize trends over a broad spectrum; they can see fluctuations in supply levels; they can see market tolerance; etc, etc. While it feels like Amazon has a key-logger on your computer, is it really any wonder they're able to essentially predict events?
So while Amazon sources products by just opening the door and letting them walk in, then tosses the supplier aside when it suits them, I'll still drink the kool-aid because there's no easier way to buy something for a dollar and sell it for two. It's exciting and fun and instantly gratifying.
Wow, that was a tangent. Been wanting to get that out for a while. The soapbox is yours.