Dear me.
First of all this is a forum. Forums are there to build a community, help other people with their problems and to have fun together. So on the one hand, i can understand your parents. I don't know how old you are, but that would make things easier.
Second, i don't know how they cought you. Did they see you playing the game? Seriously, you should know your parents and you should know, if they would allow you to play this or not. So if they would't, just play when they're not looking over your shoulder. If you're playing it on your parent's PC you're stupid.
But if your dad found it out by looking through the activity on the internet... discuss with him about that. It's your personal decision what you do on the internet, unless you're old enough/ allowed to do this. It would be asocial and unfair, if they check through your chronics. Of course, they are allowed to, but it's not very nice to do.
Otherwise... it's just a game. Find another game for you and be more careful or just go outside and do something with friends.