Whatsapp has finally activated the recall function on its app, a function which allows users to recall—or effectively delete—messages that have already been sent. You'd do well to take screenshots of messages you wish to use as legal proof or anything of the sort, lest they be recalled, leaving you in the lurch.
https://www.notebookcheck.net/Whatsapp-s-new-message-recall-feature-puts-drunk-texting-back-on-the-menu.260280.0.html