Biffins

Hi guys, I'm new here. I had a question on withdrawing money. I deposited money with Casumo but changed my mind of trying their games and decided to withdraw my money but they have blocked it saying I need to turn it over (play it all). Do I have any recourse to withdrawing my deposit from them? They said if I cancelled the account, they will retain my deposit. Thanks for your help. Biffins