Update- InstantGaming said it was an error on their part and gave me a replacement code. Everything works fine now so no harm, no foul.
I purchased the season pass from InstantGaming and suddenly I'm unable to access the Durgesh Prison DLC, so I re-enter the code and I receive the message that my pass has been banned. Wtf Ubisoft, you better have a good explanation for why you are banning the keys of paying customers.