I'm in the same boat here.

I was a 1.0 player that purchased the full 49.99 ARR CE PC edition but can't apply my CE code to my 1.0 service account. There is hope. They are handling people who created a second service account using their product keys and this feels pretty similar to that issue except we haven't consumed our key. I put in a ticket explaining the situation and hopefully it will be resolved. I'd really like to get those CE items!

I would enter in a support ticket and be as polite and descriptive as possible.

Good luck!