Hi, please make sure that the correct Steam Profile is linked to your Forum Account, and if you linked the wrong one, an administrator will be more than happy to remove the existing one and allow you to link the correct one.
If you have already linked the correct Steam Profile, and are in game, disconnect from the server, and log back in. The Booster Packs can be claimed by clicking F4, going to the "Donate" tab, and there will be a box that will say something like "You have x Unclaimed Booster Packs! Click here to claim them!" or something like that.
I do not have any administrator access to personally help you with these things, but I hope that I helped in the slightest bit by supplying information.