Once you add credits using a credit card/debit card to your CallHub account, it gets saved in your account for future use. In order to change/update card details, you just need to use your new card and add make the payment. This will replace the previous card details with the new one. You may refer to the following steps for details.
Step 1: From the dashboard, click the $ sign after logging into your account.
Step 2: Select the amount that you wish to add and click the "Add credits" button.
Step 3: Click on the "Pencil" icon to change the card.
Step 4: Enter New Credit Card detail and click "Pay Now" to make the payment.
After the payment is made, old card details will be overridden with new.