Downloading book purchased through other forums.

I purchased a PDF book from boradview press, and the only option to doanload it was adobe. Adobe only installs into iphones and ipads. I installed it on my phone, created an Adobe ID. There's no search option, and no option to download pre-purchased book. I contacted costumer support through the chat and they sent me here saying "we only provide support for people with paid subscriptions". So here I am. Does anyone have any clue on how to do it?