A disputed financial transaction in Apple Pay/Apple Card is NOT an Apple Support issue, it's an Apple Pay/Apple Card financial issue.
Take it up with the folks who can actually do something about a financial issue involving Apple Pay/Apple Card, the account reps at Goldman Sachs, the bank behind Apple Card.
Report the issue with a live message or call inside the Apple Pay/Apple Card app.
My card number and auth code were stolen through a hack of vendor payment system in summer 2021.
About a month later, the first unauthorized unknown transaction appeared in my online account.
As soon as I noticed it (within a day), I reported it using the Message function within Apple Card on my iPhone Wallet.
The helpful rep verified my account information, logged the disputed transaction, asked if there were any other disputed transactions (eventually there were three from the same hack), and immediately changed my card number, so no future transactions using the stolen credentials would be approved. My online chat was sufficient. I did not need to report the dispute in writing, as some credit card companies still do require. I did take screen shots as the chat progressed, to document everything.
The transaction immediately appeared as 'disputed' in my online account status and subsequent statements.
During the 'dispute' process, I did not owe the disputed amount, nor any interest on the disputed amount.
It took about four months, but eventually, the dispute was resolved in my favor, without any additional action from me, and the fraudulent charge was entirely removed from my account.
Another fraudulent transaction from the 2021 hack was attempted a few weeks ago, and immediately denied because again, that card number was no longer valid.