Fordmanuals.com don't buy if you have a Mac/ios

Terrible product, terrible service. If you have a Mac you can not open or view your purchase. To open the ebook that I paid $16.95 for, you have to download and install a program called PdfOwnerGuard. This program crashes upon installation on a Mac (have tried three different laptops) and iPhones and therefore the purchase is totally useless. I tried contacting customer service and they have completely ignored me for three months now.