If you don’t want to charge any more for the Bitdefender account, you can cancel the auto-renewal option. The Bitdefender notifies you via email 30 days before the auto-renewal takes place. That email will give you complete details about the renewal and a link to cancel the service. If the auto-renewal remains enabled, the Bitdefender subscription will be continued.
However, you cannot remove your credit card alone from your account; you need to cancel the auto-renewal to prevent a further deduction from your account.