PDF/i-books download won't open

I'm using an i-phone6, and I purchased a travel guide e-book off the internet. When I opened the link to download it, it said I had five downloads available in various format (ie, 5 downloads in pdf, as well as 5 in ePub). I read the instructions which said that when I downloaded the file, it would open automatically in a web browser, and then I would have to tap the screen, and it would allow me to download it to i-books or my adobe reader. I downloaded a copy of it, and it did open up. But when I tapped the screen nothing happened, no option to save it on i-books or adobe appeared. So I went back to the download page, checked to make sure I had done it correctly, which I apparently had. Then I tried to download it a second time, because I had four downloads left, and I only needed one on my phone. But this time when I clicked on the download link, the file did not open up. It did, however, remove one of my remaining downloads, so I now had only three left. I repeated this and tried to download it in a different format (ie, Epub instead of pdf), but the same thing happened. I hit download, nothing opened, but I lost one of my downloads. I have tried this several times with the same result, and now have only 1-2 downloads left in pdf and in ePUB. Can anyone explain why this is happening and how I can get the download to open again - and ideally to save it? Thank you.