So you cancelled the bonus without reading the warning ?? What did you expect? That you got your original deposit?? If they do that everyone just wager the bonus and cancel when they don't hit big and withdraw on deposit again and try again.
This is not matter of playing again or not but what I do know here, usually there is some notification if they want to cancel their bonus. It is like pop up message said that if you cancel it you will lose all your balance. It just like locked our balance thorugh your site. So people will think twice before they want to cancel it. But on this site I do not saw anything like that may be you should add this notifications
Btw on this matter, I can say the ToS tricks people too and Ojafejw did not even asking about it. May be OP need to clear something here before issues spread