Cannot find an ebook previously bought

Good morning everyone, i have a problem with an ebook bought and it's important fot my graduation.

i bought the ebook and downloaded it without an account so i could read it only in one device,  but then i tried to create an account in order to have the ebook also in my cellphone and then i didn't find theebook anymore. if i tried to download it again ADE tells me "e_lic_already_fulfilled_by_another_user".

can anyone help me? or ahould i buy the ebook again using another address and computer?

Thank you.