The player's betting pattern was identified by the company's risk management as one that gives an advantage over other players' bets. The player made bets that contradicted the spirit of fair sports betting, which led to the decision to suspend cooperation with this player, and the account has been blocked.
You should specify the nature of the violation arbitrage betting, match fixing involvement or bonus abused so that forum user will have an idea on the matters you are considering with your decision because the OP can gain the support here due to the baseless accusations due to your too much generalized reason.
Providing some proof even just a narrative will be helpful to your side. Your ToS is so scary with that kind of explanation since you can do this to anyone that wins on your casino without further explanation or simply your casino is high risk for players that is winning regularly.