WhatsApp Help Center
WhatsApp Messenger: More than 2 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere. WhatsApp is free and offers simple, secure, reliable messaging and calling, available on phones all over the world.
Seeing the message "Your phone number is banned from using WhatsApp. Contact support for help." Seeing your phone number already in WhatsApp.