Due to an unexpected occurance the 10% launch discount was not applied to purchases made during the first 90 minutes of sale. In order to receive the discount, please refund then repurchase the game. We apologize for the inconvenience.

To request a refund, the steps are as follows:

(from the Steam Client)

Help -> Steam Support

What problem are you having with this product?

Gameplay or technical issue -> I am having another problem -> I'd like to request a refund (reason: Launch discount was not applied)