Hey,
Thanks for the donation. The benefits system works automatically based on the steam ID registered with your forum account. I just took a look at your profile and I can confirm you have already been granted Diamond VIP status. This means you will have also received (or will recieve) your gold bars upon joining the game.
If you want to use your ingame chat tag you will need to activate it by going to /settings and then selecting the second tab which contains a drop down menu of all tags which are available to you.