A players balance does not belongs to the player always. When a player is earning the balance from manipulation, abusing terms, abusing bonus, fixing match, arbitraging that is not appreciated by any sportsbook then the balance is not his, even the deposit they made can be confiscated by the sportsbook according to their terms.
In that case, the betting site should have the valid proof against the users. But Coinplay has made their final decision by saying this to the mediator
In accordance with the rules of the service - we have the right to close the player's account if the player violates our rules, which was revealed by our Risk & Fraud department.
Coinplay representative hadn't provided the necessary evidence to the mediator team. While it was their last response in the forum for resolving the issue
We meant to say that you should open a complaint on Askgamblers, where we both will provide the necessary details for them to review your case.
Coinplay representative hasn't acted professionally. They haven't said anything about this issue after that. In the meantime, they used some Bitcointalk account to oppose flag. And there was suspicious activity on those accounts which has been
pointed out by Ratimov.