@OP sorry for asking but are u on really good profit on bc? To me it looks like they saw u were winning too much and went through your history to single out a bet to cancel it.
There isn't much of a history to go through based on what OP said. In his own words, he registered and made only one bet on sports when this incident happened. He had some success on casino games as well. He has also been limited by the game provider to making minimum bets because, as he says, he is a successful sport bettor.
I am going to PM the BC Game forum representative and ask them why they have not replied in this thread yet!