Fantastic win! Hope you will get that btc in your wallet soon. It irritates me when I need to wait so long for my btc tx confirmation. Can't imagine how you feeling now!!
Bitcasino is an old reputed gambling site. And many people learned about this matter. So let's think positive.

Found something at their terms and conditions::

5.8. If you win 50 bitcoins or more, we reserve the right to pay a maximum of up to 50 bitcoins per week until the full amount is settled.