I am new to Monero, but have done plenty of business with other coins. I sent a deposit to Cryptopia using "mymonero" web wallet. In the web wallet I noticed it said payment ID optional, so I did not use it. My monero never showed up at Cryptopia. I went to verify the transaction and address were correct at Cryptopia. So I clicked deposit and noticed that it says "Payment ID required" or you will lose your deposit. Did I really just lose my almost $100 worth of XMR?

Where did it go? Are they really just going to keep my XMR? If so they are absolute Crooks.