The casino made what I assume is a promise to op that if he could own up and agree on cheating or trying to cheat the casino by operating two accounts, and also writing an apology note on a public forum like this one, that they will allow him withdraw his initial deposit and maybe winnings from slot games.
I guess in that case the casino should at least allow OP to withdraw his/her initial deposit if not the winnings. OP has broken the terms of the casinos and it will be good fate of the casino to allow withdrawal of the initial deposit. I believe most people on this forum who might operate multiple accounts on online casinos should better read the terms and conditions first and avoid creating multiple accounts.
If I were the owner of the casino, I would have allowed the guy to withdraw his money, or better still, unlock the account for him to continue gambling with all profits removed. This is fair enough after an open acknowledgement, repentance and apology like this. To err is human and for the fact that casinos can hide under some facts to outsmart their customers by using the terms and conditions to cover up, they should be able to forgive in situations like this as well.
I will always say that the regulation in the world of casinos is weak, if it were to be any of my brokers, they would have released the capital a long time ago without the client even demanding it, that's what the regulation states. They would see the infraction and advise you that you've broken their terms and conditions and therefore are ending cooperation with you and urge you to withdraw all your funds before a stipulated time. That's fairness, no one has the right to unfairly take all your money just for breaching their ToS under the right regulation unless the casino can prove the customer worth the punishment through unfair plays.