U can complete payment with just the 16 digits, and not entering the CVC, expiry date and cc name? Then your app has a security issue. Better to clear cache and reinstall it. From the last $5/10 promo, i only need enter the 16 digit at payment to get the $5 off, be it on desktop or app. Nvr had to check out payment to reflect the $5 off.
Oh i meant i get to the page with the payment button.
So u mean when keying in cc number, if the cc is valid, the amt shown at the top will reduce by $20 ?