iCloud Drive file: roll back to previous verion

I have an excel document in my iCloud Drive that I access monthly. This morning I accessed the document on my iPhone, via the excel app. It opened fine, I swapped to another app and then flicked back to the document. It had closed, but when I tried to reopen it, it I received the following error:

"Excel cannot open the file 'ABCDEF.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."

I closed the app, and tried to open it via my Mac, at which point it opened as a tab delimited file and the contents were garbled. A mixture of characters.

I need to access this data, and I want to find out how to access a previous version? A version from before this morning would be fine. But I don’t see anyway to access back ups of iCloud Drive files.

Anyone have any ideas?

Thanks so much!