Apple actually does have pretty good support for this sort of case. I went wrong. Here is that the account was in a state where support even high-level Support was not authorized to unlock it.

I have personal experience here. I was gifted a meaningful chunk of Apple gift cards. I redeemed them to a secondary Apple ID as this ID is rarely used. It got locked when I tried to spend the Apple gift cards.

It took a couple tries over a few weeks, but Apple support were very helpful and able to unlock the account. Where I must've got lucky is the automated system must've allowed the Support to take this action and it sounds like in the case here whatever fraud flag triggered issued to far more severe response.

My case I should add the gift cards were totally valid. It just was rarely used to count. That might explain why it was easier to resolve in any event. They absolutely as human support. The real issue is when human support can't overrule the computer.