Have you done the walkthrough but redeemed the rewards on the Prime Gaming website? If so, have you checked if they are in your partner redemption history? If you don’t see your Gear Drop there, you’ll need to restore your connection. To do so, you need to re-connect your Twitch account to your Bungie.net account. You may want to re-link your accounts together then wait until next month to claim that Gear Drop. Another important thing, have you verified that all linked accounts are correct? If so, do you share your Prime account with someone who may have redeemed the rewards before you? As the reward can only be collected on one account. Note that you are not the only one facing this problem, several other players were not successful in redeeming their rewards.