Vuescan review: No product, no refund

On the 22nd of March I paid US$ 79.95 for software called Vuescan. When I installed it it wouldn't work with my specific scanner so I contacted the company and asked if they can give me a refund. They simply said no because they do not guarantee that it will work with all scanners. On the front page of their website they make big promises: "VueScan is the world's most widely used scanning software, with more than 5 million copies downloaded.

VueScan is easy to use, saves you time and improves your productivity. It saves you money by letting you continue using your existing scanner, and it gives you higher quality scans than the software that comes with your scanner."

I didn't test the software first like they suggest on the site but paid for it in good faith that if it turned out not to work I could simply get a refund. No such luck. I do not understand why it is so difficult to refund someone their money if the product doesn't deliver. I am just starting up a small business and that money is a lot to me. If so many other internet businesses selling software can give refunds, why can't they?