Two Accounts, one is activated, the other one is broken

[Mwynn]

I might post this here, I even have sent an E-Mail to the SE Support about this yet ...

The Account I play the whole time is a Non Steam Account which I use Steam to track the Hours for.
This means, I own actually two Keys, one is for the Non Steam Account which is activated and the other one comes from Steam actually because I bought A Realm Reborn there.

Refunding doesn't work since I use Steam for my Non Steam Account to track the Hours and the Steam Overlay.

So I have a Steam Key which is not activated and giving it away is useless since then you can't buy the Heavensward Expansion in Steam since the one who received the Code from me won't be able to buy it.
(It requires to have A Realm Reborn in the Library)

Question is now, what the Hell am I doing with the Non-Registered Steam Key?
It hasn't been activated by almost a Year now and it's still remaining in the Library with no use for me.

Refunding? Won't work, Steam already has tracked +2 Hours because of the Non-Steam Account which I use to play...

Locking the Steam Key Code and receiving a Non Steam Code instead? Support said, it won't work that Way.