Bought premium edition (I like to support the game - yes it is overpriced) and got codes by email.
Entered code for one month extension of subscription - it was accepted.
Entered code for the expansion itself so I could get whatever items are available now - and play the new race now - and code was rejected as invalid. Tried 7 times same result (cut and paste I wasn't mistyping it).
Should I start worrying about my "investment" or are you just a bit slow in updating the store filters for the brand new codes?