u/Excellent-Fill-2165

I accidentally made a payment to an old (2022) closed account instead of my current account. After spending several hours navigating the disaster that is Capital One customer service, I’m told that they can see the payment, the amount, and the date that it was paid, but can’t apply it to my current account unless I provide them with the 16 digit card number from the old account.
Despite them being able to see it, access it using my name, DOB etc. there is no other piece of information that I can provide apart from a 4 year old card number to get my payment either refunded, or credited.
Delightful.
Now, knowing this, is there any way to obtain this number?