Hopefully they can also clarify how to avail of an MSFS version discount available for previous owners of KORD v2 in P3d5 which I am.
Surely they can't, they are just a payment provider, and they only thing they can help you with, is the password problem you are having on their own site.
About the upgrade offer, we sent an email to all registered users of KORD V2 ( those that bought it on our site, of course ), with the upgrade offer when KORD V2 for MSFS came out, in September 2020. If you lost it or you changed email, you should contact our support email instead.