I had the same issue, tried a hundred times with different combinations of billing and shipping address to see if that was why it was failing. finally I got in touch with the Apple support iMessage thing (which was broken all morning). The message representative told me to just use my regular card and Apple would "make it right" and all I had to do was call the Apple billing department to fix it. The Apple billing department has no idea what's going on and has no way to fix it except for me paying off my entire phone today.
I tried to go into my CitizenOne account and change the payment method but it won't let me. I called CitizenOne and waited on hold for an hour they don't know what's up. They said "maybe try again later".
So far, no way to do this with an Apple Card except to cancel and re-order in which case I get my phone late...
EDIT I tried to CitizenOne account again and this time it worked. I had to login, "add a new loan" using my new iPhone loan, and change the payment card. So now I'm good I guess except for that $6.50 premium I paid on the first payment and taxes due to Apple's screw up!
I tried to go into my CitizenOne account and change the payment method but it won't let me. I called CitizenOne and waited on hold for an hour they don't know what's up. They said "maybe try again later".
So far, no way to do this with an Apple Card except to cancel and re-order in which case I get my phone late...
EDIT I tried to CitizenOne account again and this time it worked. I had to login, "add a new loan" using my new iPhone loan, and change the payment card. So now I'm good I guess except for that $6.50 premium I paid on the first payment and taxes due to Apple's screw up!