RECOVER YOUR DOCUMENTS!
After I had the same problem as you, I searched for a solution to get my documents back. And I found one!!! This evening I recovered all of my documents.
How to do?
First: You can only do that if you did use "icloud documents sync" also on your Mac (don't know if the windows variant also works) before icloud deleted your documents.
My example shows the way with numbers documents:
1. Watch at your mac for the folder /user/library/Mobile Documents/com~apple~numbers/documents. You should find some folders like myDocumentsName.numbers-tef. Take care with this! These are your lost documents. Copy the folders to another directory (save it).
2. Then you need a document in old numbers style (like the ...numbers-tef folders). I had that on my iDisk. So I used my ipad to recover the document from the iDisk to ios numbers. (it‘s totally equal if that is the correct document or not. You only need a document in old style in numbers ios).
3. Rename that document within ios numbers to the name of a document you lost.
4. After you renamed the document in ios numbers it gets uploaded to the icloud. Then you will see it at icloud.com and a few minutes later it gets synced into the com~apple~numbers folders on your mac.
5. replace the document you find there with the document you saved before out of that folder and wait until that change gets synced in the icloud.
TADA now your ios devices will update its document and you will have your old documents back.