The official customer support contact for Visa Signature card-related withdrawal issues typically involves contacting the issuing bank's support line or Visa customer service, such as Visa International Customer Service representatives. For specific emergencies, Visa Signature cardholders also have access to 24/7 Global Customer Assistance Service. For example, cardholders can contact +7 (495) 937 6453 or [email protected] for insurance and support inquiries.