Update your iCloud billing information

Hi, I got an email with this message: “Update your iCloud billing information to keep your storage upgrade.”

I entered an other credit card but nothing has changed and I still get a warning (in the iCloud settings) about needing to update my payment details because there was a problem with my payment details. The card works fine on other payments, and following the “update payment” in the settings doesn’t solve the problem.

what can I do?! I can’t afford to lose the storage.

thanks.