How to delete a WhatsApp account?
The description of the service:
WhatsApp Messenger is a free, cross-platform, end-to-end encrypted instant messaging, proprietary and social media application for smartphones. It uses the Internet to make voice calls, one to one video calls; send text messages, documents, PDF files, images, GIF, videos, user location, audio files, phone contacts and voice notes to other users using standard cellular mobile numbers.
In the settings mobile app: Settings - Account - Delete account.