It's not scam!!!   This issue is quite often with any!!! exchanges.   Poloniex, Cryptopia, kraken, cobinhood(terrible experience!!! stay away from this exchange!!!) ......
I sent ETH to BIBOX and waited and waited... 6Hrs later I sent an email and received the fund to my account within a minute. (I was surprised how fast they responded)  
Luckily the price hasn't changed the coin that I wanted buy.
When you get conformed from the blockchain explorer, you need to check your account and if order hasn't put thru, then email them right a way for the solution.