According to the Terms of Use of Pokémon.com and PokémonTCG.com, users
are prohibited from creating more than one Trainer Club account.
Because of this, the support team cannot guarantee any code or
card/deck transfer between accounts.
You can, however, submit a claim if an accident had actually occurred with the input of account information. In your case, this did not happen, but you may be able to explain the situation to their support team and get back on track. Here's some more info to keep in mind:
Please retain your code cards and transaction ID numbers for future
reference. Your code cards and transaction ID numbers are vital to
servicing any code redemption issue. Without this information we may
not be able to fully address your issue, and your claim may be
dismissed.
We reserve the right to determine the validity of any information
submitted for the purposes of your code redemption investigation.
Providing false or altered information may result in action being
taken against your account.
I wouldn't recommend submitting a claim due to the fact that you're underage and have already provided false information, but it may be possible to get a parent to send an email and set up a new account alongside a parent account. I couldn't find any more information regarding the validity of codes following account deletion, they're rather strict in terms of rules (they're put in place to avoid situations like this). Best of luck.