Sadly, that's their business model. Unacceptable, I agree, but that's the way they roll. I usually sniff around FT before flying a carrier I've not used before.

While you're waiting for Spirit, you might want to review the credit cards you used to purchase this fare. Many cards have trip delay and trip interruption coverage which might get you a few bucks. I was surprised to learn that my Wells-Fargo card even has this despite not being a "travel" card.