Everything I just type got deleted. I'll try once more but NOW I"M ANGRY!!!
I bought one more for those Game Pass 3-month codes. Figured for $9, I'd see if I could add time to my Xbox Game Pass Ultimate account like you all say I can. Only I paid the $9, tried to apply the code to my account, and got a message about "trial" codes only being 1 per account. I did NOT buy the Game Pass Ultimate code, but the Game Pass 3-month membershiip immediately mentioned above... so NO IDEA what I did wrong. I've emailed CDKeys explaining the whole thing, and explaining I'm still waiting on a refund of one of my codes from last week, and now this $9 purchase that didn't work. :(
It seems that you got the wrong code. Some codes being sent for this deal are for new accounts/subscribers only. You should get a refund like others without any issue.
I will remove this deal from list until it gets fixed.