Cannot change Apple billing info - only one hacked card.

Unless the iCloud subscription is set to renew, before the new card arrives you should have no issue. Its not going to end before its set to renew, and won't even try to charge the hacked card until it actually needs to. When is your renewal date?

If the subscription is set to renew before the new card arrives, then I don't believe there is any way to stop it.

You can try to use one of the contact methods for Apple in the following support document and see what they say.

click here ➜ Contact Apple for support and service - Apple Support

Why do you need to communicate with Apple?

Access your account and update your payment method by following the steps in the support document linked below.

click here ➜ If you need to change or update your Apple ID payment method - Apple Support