Please you will have to follow up with stake support and if the large is a result of their networks, they have to pay you cahs also note that most of the casinos have their T&C that may not allow have your cash out but just keep us updated on how it goes.
Also, i wish if OP could move this thread to scam accusation or should have posted this in the stake AN thread so as to notify the stake team. I want to see how stake will take up this matter and what are their say about this unfortunate situation.