I didn't even realize I was eligible for this reward, but I see it was applied to my account. So not sure how long it took, but I trust they'll get it added on there for you!
When I followed the instructions, it worked instantly (just go and pretend like you're going to purchase the add-ons, but they show as $0, so no charge). Good luck!
I didn't know I could report it so I actually opened a link AND then just deleted the email... will see if I can find it in another folder and report it. Actually I think I had two of them.