looking for specific Fdcpa section where the law states it is a violation to collect on minors

Unless there was an adult co-signer involved in the loan, the debt is not valid.

There are a few exceptions. If the minor misrepresented himself as an adult, the contract could be enforcable.

You won't see anything in FDCPA. Look at your local state laws on the subject.

The FDCPA does not address minors, only collection practices in general. You need to check the state where the debt occured to see what the legal age for a contract is.
If you were under the legal age in your state when you entered into the contract for the debt, then no one can collect it and you should contact your State Attorney General and file a complaint with the Consumer Protection Division at the Attorney General Office.