The payments industry is rife with nonsense like this. At a fintech startup I was working with, we built a "shadow ledger" because we couldn't trust a 3rd part

The payments industry is rife with nonsense like this. At a fintech startup I was working with, we built a "shadow ledger" because we couldn't trust a 3rd party PP to give us the correct information, which would otherwise allow double spending on accounts. We tried 3 different (major!) PPs - they ALL had similar flaws.