We can clearly see on the https://blockchain.info/address/1PbKZZXPLVLzfhsKQxtXjujRa2a5vmpb9p that this deposit was confirmed and was not "double spent".. any previous transactions from the originating address also shows no kind of "double spent" transactions. The transaction also has a fee in which it prevents from being "double spent". You also can't reason out the location since i do use vpns to log and play on different sites.

You can't just hold someone else bitcoins for the speculation of cheating. If you guys are getting "double spend" attacks which i think is very hard to do, then im sorry to hear that, maybe you should put up more security to battle that kind of attack.