Its better to create another thread on scam accusion then provide a proof that you got scam by this satoshi dice, then people can discuss about your problem because this 0.4 btc is a huge money, you also mentioned about that you already contacting the support but its appears that its never chat back on you.
In fact the OP did not send 0.4 BTC to the Satoshi dice, but only 0.04 BT and did not present other evidence.
OP transaction
https://www.blockchain.com/btc/tx/f8ca704cc3c877d8e8bef695414ee8953eeda2a1d9179a0f772499895e55d27d