If you have problems with these Exchanges – check your wallets on the Blockchain.
There seems to be a pattern to this back-door fraud that the Blockchain will reveal: even though the Exchange tells you that you have coins in your wallet – the Blockchain will reveal that soon after you deposited Coins into your wallet – they vanished into another wallet: without U being informed.
That is actually pretty 'normal' behaviour for most "online" services, like exchanges, where you don't control the private keys and just have an "account balance".
The service controls the address, you deposit coins into 'your' unique deposit address... the service then credits the matching amount of coins to your account... effectively like a bank account really. They are then free to use these coins for whatever they want (like fulfilling other peoples withdrawls)... much like when you deposit $100 into your local bank, they don't put THAT specific $100 note aside for just you...
Then when you want to withdraw your coins, they just send you the matching amount using coins from any of the addresses they control.
Using a system like this actually offers the company some good benefits... in that it becomes possible to minimise transaction inputs, by having more flexibility to match a withdrawl request with an appropriately sized deposit amounts...
AND (despite the obvious security risks of letting "RandomCompany" Ltd. look after your coins) you get the added benefit of coin mixing!
