I have scanned QR code on merchant's device but have not received their card or voucher.

Downloading Cards and Vouchers is always dependent on the internet connection of customer phone. If the internet connection is slow, it will take longer than usual to receive the Card and Vouchers. But when the connection is stable, then the downloading of Cards and vouchers should be instantaneous. To speed up the download of the Cards and Vouchers, please tap the refresh icon.