They don't even create a unique deposit address for each of users. They give a single address to all users and ask them to provide their transaction ID.
This system can't work in the long run. It can only work with a very small use base, but if they want a future in this industry they have to change this as soon as possible.
@Pitibet
How many members do you have working in your support team 24/7 who credit coins to player accounts? You need staff 24/7 if transactions are to be credited manually. Consider a scenario where you suddenly receive 100s of transactions, how are you going to credit them to the respective accounts in a reasonable timeframe?
How will your staff deal with other user inquiries if they sort out deposits around the clock? How big is your team?