We are in the process of replacing our billing system which will allow a lot more flexibility around payments, including bank account debits. This is a 12 month project and should be completed by the middle of 2021, with some reckon product users (Elite, Docs) seeing changes starting from January 2021.
It should be possible to change the payment details of reckon fees easily. I will have exactly the problem above at my next payment cycle as I have a new credit card.