In the first place,why would you gamble to such shady sites and rant about being scammed?
Because there are many people "claimed" they've won huge amount from there.
Anyways,move this to scam accusation and directly ask for support and look for their ANN thread here if they even have one.
Its useless to ask their support since they won't answer any of your question. They also don't have any ANN thread on here.
This thread should be moved to scam accusation thread just like other said on above.
P.S your money won't be back because 999dice is well known scam gambling site