Betting on a bad line doesn't make you a cheater. The issue I have with these guys is they aren't being up front about what happened. Stop using it as an excuse for 1xbit to ignore them.
If I saw a line on sportsbet.io, or Stake, or any other reputable sportsbook right now for a match that had just ended, I'd bet on the winner. They might void the bet, or they might just pay me, I don't know. What I do know is that they wouldn't just take my balance for placing the bet.
Taking advantage when the House makes a mistake (like setting a bad line, or exposing a card) doesn't make you a cheater.
You claim that you are betting on a sport events, knowing its result? Did you just confirm that you did it and are doing this or is it still a hypothetical situation?
Somehow I can't imagine you doing something like that ..
I've never seen a line that was still open after a match ended. That's a pretty stupid and expensive mistake for a sportsbook to make, unless they decided they will just steal the balance from any player that accepts their wager. I really don't see any other explanation for this happening so frequently on 1xbit other than they view the income from stolen funds as part of their business model.