That's a no sense, because If I make profit they have the power to forfeit my winnings, but If I lose they won't say anything and keep the money.
This is unfortunate, but this is the reality.
This is a player's responsibility to check the TOS page before they agree with the TOS. You cannot really blame them because they banned your account and confiscated the winnings. You are from a restricted country and they have the rights to ban you. As I can see, Rollbit always pop up a notification when they detect a player from a restricted country. So, it is you who played there knowing that you are not allowed to play there. Sorry for your loss.