I have a code for a free copy of Call Of Duty (Purchased a HP computer)but I can’t redeem it here on my battlenet account.
It should be able as Blizzard work together with Activision.
Can’t find any forum here on Blizzard site.
You can see how to redeem codes here. However, I don’t know how that promotion you got works, so you might have to do something else to claim it; did it come with instructions on how to claim the code?