I am experiencing the same error, from adding a credit card to creating a new campaign.
But there is one point to note:
Has your apple account successfully submid the apple store app? That's what we may not be able to create a search ad of apple.
i am facing this error why i am trying to sign up search ads basic account. My app is live on app store but i cant sign up for basic account. I have emailed to support team for comment on this