Halo Rockstar Promotion Issue

Is anyone else having an issue getting the last warthog coating?

The website keeps telling me it’s the next unlock but when ever I put a code in it just gives me xp bonuses. I’ve entered like 4 codes now and it just keeps getting pushed to the next unlock.

Edit: I guess the last unlock is for Circle K specific Rockstar cans. So if anyone happens to have an extra code I could trade my normal code for your Circle K one. If you have the coating already you still get the XP Boosts and stuff.