Hi, DarkoK3,
NetBet was formerly Poker 770 it is *possible* that the mix-up is due to the changeover.
I suggest that you request a transaction history using the poker client.
Then send an email to their support address giving all the dates and methods of all deposits.
Remember to work with the support person as calmly and patiently as you can -- you want them to be on your side.
I suggest that you don't make a deposit and claim the bonus -- once they figure out that this is NOT your first deposit, it will look bad for you.
Patience is key here.
Best of luck,

VS