User Story: As a mobile banking customer, I want to freeze my debit card instantly from the app, so that I can prevent unauthorized transactions when my card is lost or stolen. Acceptance Criteria: User can access a card freeze option inside the mobile app. User receives confirmation after successfully freezing the card. Frozen cards cannot process new transactions until reactivated. User can unfreeze the card from the same account. Priority: High Notes: This feature improves account security and gives users faster control over card access.