It's a bonus mate! you can't use the free balance for bonus buy ~XD

Still on this month, If not wrong maybe around 1 week or 10 days ago. I got a promotion on my email and just doing some fun taking this promotion, I don't even know the slot I was playing so betting with high balance and suddenly the balance increase 5x times ~LOL.

Trying to complete the wager only 30% left, If success not bad you can win 15mBTC.