I don't really understand... What were you expecting?
It's a casino. Their only goal is to make money.
If you're a big player that means you made big wins. They want to check that those wins are legitimate before paying you out.
It would be the exact same thing in a real life casino. If you win a too high amount they will make you wait so they can analyse the pictures taken by cameras to be sure that you haven't cheated.
That's just to protect themselves from new hackers and bug exploiters that's all. Nothing unusual.
No.... They merely excuses not to pay out. Phone off ? No email reply ? Come on dude.
Nah if they wanted to not pay they wouldn't have, like betcoin did.
They were just winning some time that's all.
Of course I don't believe a second that all those incidents sadly happened at this moment ^^
But they were excuses to check on the guys winning not excuses to not pay. Otherwise they simply wouldn't have paid

Or at least not without the "are you really the account owner" card.