Vendor ID

I downloaded an ebook in October, which I need next week. All good. Today I followed the instructions to authorise my computer to try and sync it with my iPad.

Now 't access the ebook at all. It's asking for a vendor ID and password. I never received these when  downloaded it originally just added my Adobe I'd at the time. i need to access the book but I can't seem to get any help. I've tried calling and emailing  ebook store. No help there.