They don't say in any part that they are allowed to confiscate any balance. They said that they could not be able to make the withdrawal. But, they already made some withdrawals, so this is not a problem for them.
I don't know what should i do if i was in +. But probably the same. Refund my balance or my deposits.
The question here is that they are stealing money from a person that lost already money in their casino.
You violated their ToS and they used this as a major tool to block your account. Didn't you check that they restricted your country before you joined this site? And if you knowingly gambled even though your country was restricted, you put your own funds at risk. Just because you're losing money doesn't mean they won't block your account. It could also be that you won so well that they thought you would recover all your losses.