Hi Haze,
We've just taken a look into this issue for you and can see that you've successfully claimed your Booster Pack upgrade on the server. If you're still missing any items, it's likely your playing on a different Steam profile to the one you had previously. In addition you may have purchased upgrades on a different ZARP account which is not linked to your Steam profile yet. Currently your account is linked to
steamcommunity.com/profiles/76561198094477618 and has 1 Booster Pack upgrade that was successfully claimed on the server.
Hope that helps and thanks for supporting ZARP!