That's probably not a withdrawal - it was moved by whoever owns the address, which the OP claims belongs to PrimeDice but it doesn't seem to be linked to any known PrimeDice wallets and there is no 14.2 BTC deposit to that address. I think the OP is not telling the whole story.
Wait a moment.
Are you telling me that they can move the funds whenever they want?
If yes we need to follow all movements and they seem to go here
https://www.blockchain.com/btc/address/16qfh6U6zBuWtqtjfRLWxAu8HyEJNiB5Nda 9000 moved BTC address.
Edit, maybe OP is using 2 accounts? and they have locked one?