Why not ask OP to publish his last 5 bet slips or so? An abuser is quite easy to spot. Pretty sure it must be on small unknown leagues/matches.
I'll stop my comment if his bet was a simple MU vs City 1x2 bet and the like.
He said that his account is blocked and closed. I don't think he can do that, but the BK8.Official admin can if both parties agree to it. I would say it also depends on where you live. If his bets are on a small unknown league in a 3rd-world country, and he lives thousands of kilometers away in a Western nation, I would agree with you that it looks bad. But if he lives in or around the country whose matches he bets on, that's totally different.
While details are best to be open for transparency for the players' side, it is going to sound like "how to cheat the casino" and "this what makes you caught." Therefore termination based on the breach of rules is used. Common sense should also be used in this instance since the amount in question is always small and it's always sports betting instance.
But where do we draw the line? How do we determine who is telling the truth and who isn't? Choosing sides without knowing the facts isn't the right way to do it. So OP is lying in this case with no presented evidence whatsoever. If you or me made a similar accusation tomorrow in the same way, would we also be lying or are we telling the truth because we are somewhat more trusted than OP is?