If you received an error when trying to purchase a zyBook that contains the words "Card declined", you should first check to make sure that you typed all of your information correctly. It might help to clear out all of the fields and retype them.
If you are still having trouble, this may mean that your bank does not approve of the transaction. In that case, you should reach out to your bank to learn more.
In the meantime, please feel free to reach out email@example.com and our support team would be happy to grant you a temporary subscription to the zyBook while you work with your bank to resolve the issue. Make sure you let the support team know your zyBook code so that they can assist you more quickly.