It’s fixed for me now! Yay thank you so much! So if anyone had the same problem as me, I used all my foils and one toy didn’t upgrade to gold. Right now I just clicked on the machine in Valdrakken, and I got foils! I went to the machine in Stormwind and I can hand in the quest to upgrade my remaining toy and it worked! Got my upgraded toy and finished the achievement woo!
So if anyone is missing foils, click the Valdrakken machine for the amount you need to upgrade the missing toys, and go to your main city. For me it was Stormwind but I guess the Orgrimmar one should work too? Not sure, I can only speak for what happened to me now. Hope it helps.
Thank you again <3