What happened:
Five days ago, user tobericher (=the victim) deposited 16 Bitcoin to BITMIXCOIN.IO (=the scammer).
A few hours later, escrow zazarb announced that he returned the 5 Bitcoin escrow he was holding for Bitmixcoin.
Yesterday, user tobericher posted for the first time, claiming his email about his 16 Bitcoin deposit was ignored by Bitmixcoin.
Today, tobericher emailed me his Letter of Guarantee, which I've verified to be authentic. I can confirm he sent 16 Bitcoin to Bitmixcoin's deposit address, and never received his mixed coins.

Scammers Profile Link:
BITMIXCOIN.IO

Reference Link:
Start reading from here

Amount Scammed:
16 Bitcoin, but if this is an exit scam, the total will go up much more. They claimed their weekly mixed amount was around 2500 Bitcoin.

Payment Method:
Bitcoin

Proof of Payment:
In my posession, verified by me, confirmed by Vod and confirmed by Lutpin.

Additional Notes:
The timing looks very much like an exit scam: wait until a big deposit comes in, take back the escrowed amount, and stop withdrawals.
If this is a technical glitch, please send the funds to the right address and I'll confirm that here.
It's not a technical glitch, scammer BITMIXCOIN.IO denies having received the deposit.

Side Note:
I didn't trust them from the start, but there was no evidence yet