STEPS TO RECOVER DELETED WHATSAPP MESSAGES
STEP 1 : Go to Mobile Settings, click on option called Apps. In some mobile, settings may vary for example, In Vivo mobile, you have to click on more settings then select option called App Manager.
STEP 2: Select Whatsapp option, then select storage option, Click on clear Data, close the settings app.
STEP 3: Go to File Manager App (which is a default App in Mobile or else download File Manager in PlayStore) in your Mobile.Search for Whatsapp Folder,under that click on Database folder
You can see option like msgstore.db.crypt12
STEP 4: Click on Edit, Rename it as backup-msgstore.db.crypt12. Click Save
Go back to Whatsapp .Enter mobile number,click Agree&Continue.You can see Backup option; click backup and continue. All your deleted messages are restored now.