I love when companies toss around phrases like "for security reasons". If someone types in a code, what danger would there be to the company if a screen popped up to tell them "This trial account has not yet started. Activate?". Then I could click "No" and know that the code is good. Simple.
My intent was to give my nephew the trial, and then pay for his subscription if he liked it, but I wanted something physical to put in the card. They make things unnecessarily too complicated. Looks like he's getting a GameStop gift card again. Sigh.