Can you update the payment method on an order made in the Apple Store?

I placed an order for an apple pencil and iPad, the pencil shipped but while waiting for the iPad I needed to order a new debit card. Now my iPad won't ship because my old card information is incorrect. But whenever I get ahold of support they say they recommend getting ahold of the bank (but there isn't anything wrong with my account, just that my card is new) or that all they can do is cancel my order that I've waited over a month for. Is this correct or am I not phrasing it right?