Do you have a single posek who corroborates what you said in that thread?
not of hand. I have to remember which seforim I saw at the time...i will bln post when i find. I can assure you this, there ain't no consensus either way.
The concept is simple, merchants have an agreement with visa and banks that they will get paid by them for an approved swipe.
There is a totally separate agreement where the CC company will bill you for amounts charged. Agreement A is not dependent on the fulfilment of agreement B.
This is at best an eved kenani situation between the consumer and the merchant.
Disclaimer:
I have no idea how this affects hilchos ribbis. I'm just pointing out the glaring differences mentioned by poskim in other contexts.