When you bought from NewEgg they will have given you an order reference code. It will be in the emails they sent you. If you want this clarifying then forward your receipt to me (remove any information you don't want me to see first).
This is the one you use in the 'Promotion' field when buying Dark Physics. You only have 1 order reference from NewEgg (per order), so it shouldn't be too hard to find.
"Bite my shiny metal ass" - Bender, Futurama
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