My bad !

 Seems that is been possible to withdraw lower amounts from the promotions !

Good catch, maybe most of us missed above post from 8bet so we keep on asking to each other about the free spins winning.
This information should be available on the website at least under the terms of the bonus/promo page or withdrawal page.
It will always make confusion for those who are not aware about this situation because most players will be referring to the minimum withdraw information under the withdraw menu.