Three thousand dollars left on the phone
A father took a call. The caller made it urgent, talked him into buying gift cards, about three thousand dollars in all, and had him read each gift card to the person on the phone. That post did not name a gift card brand. The money left the house because the new gift cards were read to the person on the phone, not because an old gift card's balance was looked up and came back as zero.
The caller rushes, names which gift card to buy, asks for the card number, and asks the father to read the scratched gift card out. Government, a boss, a relative in trouble, tech support, a prize, a utility bill, someone just met online: those scenes are in the brands' own scam notes. What they share is the request to buy gift cards and then hand the gift cards over.
A balance does not bring the gift card back
Before the gift cards are bought, there is no balance to check. After the gift cards are bought and have been read out, another balance check shows money the person on the phone can already spend, or it shows zero. Whether the figure changes does not pull the gift card back.
This page has no balance-check entry to follow. A check reads the amount the issuer returns now. Reading the gift card out happens before that check, and outside it.
If someone tells you to buy gift cards and read the gift cards out, does a balance check help?
It does not. The scam is reading the gift card out, not the balance figure. Once the gift card is read to the person on the phone, you no longer control the money on that gift card.
Lowe's removed gift cards from self-checkout because someone on a phone was coaching the cashier through the sale, not because a package on the shelf had been swapped. That case is on the US Lowe's page. The phone's instructions are not written out here.