This is an old post, but will post this in case it helps anyone else.
We have been struggling with this for the past 2 weeks while trying to do testing and we eventually tried incognito mode on Chrome and it worked! We still not to sure why incognito mode would work though?
Online payment using Absa credit card was possible only in incognito mode until recently.
Now even in incognito mode it does not work any more.
An important small international payment failed. Showed "payment details could not be verified.
Trying a local online purchase, it keeps saying "connection reset".
Incognito is not going to use any existing cookies or cache. Maybe you have something cached that's causing a problem. Try to delete your cache and temporary files from within Chrome/FF/etc.and try again