I haven´t received the whole money. Only my deposit. But the profits where retained.
I think this is fair, it is good that they returned your money that you deposited, they do not have to return the profits as long as there is a dispute between you and them about these profits.
Since they returned the capital to you, this indicates goodwill by the site. According to their point of view, you violated the terms of service, so they cannot give you the profits that you obtained, and they returned the deposit to you and closed your account as a result.
This isn't fair because we don't know what is the truth, I know a casino won't risk their reputation for few thousand dollars but from OPs perspective he has all the rights to receive the rewards or exact reasons with convincing proof that he got violated. But the arbitrage betting is kind of complicated too so we can't argue much about it.