If you receive a duplicate error when trying to redeem the key, the quickest way to receive a solution is a confirmation from Platform’s Support when the key was originally redeemed - the Activation Date.
This solution, with a little help from your side will make the reporting procedure faster and more seamless - having the evidence already we will be able to verify and acknowledge the report right away.
Example on how to receive an Activation Date from Steam:
- Contact the Steam’s Support directly
- Make sure to include the key in the initial message with your request
- Then, after receiving a response - take a screenshot of your full desktop screen (including task bar with time and date) directly of the Steam app that includes your request + response and provide us with it when reporting the case.
Example of a correctly taken screenshot: