If you've participated in multiple on-forum altcoin giveaways, the bans for said offenses can overlap (especially when the number of users getting banned for participating in that particular giveaway is in the hundreds or thousands since the way SMF handles mass bans is somewhat wonky). Looking at the banned account, I suspect that was the case here. The ban should end in 3 days (unless, of course, you get banned for participating in another giveaway).