IA/KB: No-VAT flag must stick before swipe

Seen: NU4122-JENILY-2 (Neil) — no-VAT selected then reload re-applied VAT; client swiped higher amount and asked VAT refund as individual.

Rule: Confirm no-VAT (or with-VAT) on the final amount before card/EFT posts. After order processed, VAT cannot be reversed for a refund (Eric).

Do not promise post-payment invoice amendment to remove VAT.