US law requires that F9 cancel and fully refund any ticket purchased for travel 7+ days out within 24 hours of purchase. Not so for the bells and whistles. The T&C for the program seem to be fairly clear, e.g. that you may cancel at any time, but you won't get your funds back (and you must cancel by midnight of the last day of your membership to avoid being charged for another year).
https://www.flyfrontier.com/ways-to-...nd-conditions/