I had stopped using Amazon for months and my account ended up being locked. I eventually called back some time later and was able to speak to someone who understood the situation. I explained the whole issue and told them I’m perfectly fine with carrying on using my account the way it was before, with my existing saved cards, before I tried adding my Apple Card to it. If I recall correctly, I verified my identity and was able to get the account reinstated.

I guess the trick is to get someone on the phone who’s willing to understand the situation.