Some preset companies don't offer refunds, why the heck is that?! If you don't like something, you shouldn't have to keep it - thats just good business.
Sometimes you just don't know if Lightroom presets will fit your style until you try them and I want to take away any risk that you won't love them.
If you don't love these presets, I don't deserve your money. If you want a refund in 30 days I'll refund you immediately with no questions asked and we can still be friends :)