They even cited that the charge was for "mining fees." Are you kidding me? Mining fees for USDT. In short, I rushed to the live support, and we had a very heated argument that later made them apologize.
You probably won the argument because they understands the legal count charge as the case maybe if that was a centralized exchange you used.
I just hope you don't think you've won and think everything would go smooth for a long term because if that platform has been such a dubious one for users and some like you were able to drag them and won without a third party in the resolution, I think such platform shouldn't be trusted because they'll definitely find other means to extract that $8 from you and if you don't keep heads down, it'd happen in a way you never expected probably they'll increase their brokers revenue stream of merchants and then, these merchants will have to decrease their exchange rates which orderly would be that you'll sell at lower rate compared to some other exchange.
So I will just advice that you exit the exchange because already, their compromise after your argument with them sound a bit less reputable to be trusted.