Dear bitcointalk community, after discussing with our Sportsbook provider BTi, we were unable to get their cooperation to disclose their detection algorithms, even to just a select few reputable members of the community.
We decided on an alternative which is to donate the full sum involved (20 mBTC) to a charity of the community's choosing. In addition, BTC365 will match this donation (another 20 MBTC) as a gesture of goodwill and gratitude. We put it to the community to come forward with up to two charity organizations to receive the donations.

We have learned much from this incident and have patched our Customer Support process and Terms and Condition accordingly. BTC365 is committed to providing the best betting experience to our  players. We seek the community's understanding that we are unable to do business with syndicates, informed punters, or any party that enjoys an unfair edge over our normal customers.

@LoyceV we are holding the 20 mBTC. BTi is unable to disclose their detection algorithms, even in the presence of an NDA.

So to summarize: you took 20 mBTC from a user because of an unproven accusation of something that isn't forbidden by any of the rules.