Apple Pay charging wrong card
So within my Apple Wallet I have 3 cards. Let's call them Card A, Card B, and Card C.
Card A is set as the Default Card in my Apple ID settings.
When I start a subscription to Apple One, it asks me which card from my Wallet I want to use for the subscription.
I select Card B.
When the time for payment comes around at the end of the month, it charges Card A.
I delete Card A, and the following month it still charges Card A.
I spoke to Apple support and the guy told me this is normal behaviour (???). He said the only way to use 2 cards is to every time I want to spend, I have to go into my Apple ID and change the default payment. Surely this is wrong? I mean if it asks you which card you want to use for the payment, surely that's so that you can use a different card? Otherwise what's the point in asking?
iPhone 13 Pro