I have tried for four days to log in to ADE.

I seem to be unable to download books from ADE because my login fails every time.  I have reset my password three times but still I can't get past the login.  Last time it asked for a Vendor ID and I don't know what that means or where I get one.  I have bought three books from e-Books but am unable to download them to my Kobo.  Help!!