WhatsApp software update

This is regarding WhatsApp software update. When I open the app there's a message coming to update the WhatsApp orelse it will be expired in one day. When I click the update button it is showing the previous owners email addresses as the iCloud email address. But my all the settings have been changed to my email address and iCloud password changed. When I go to forgot password option and enter my email address, recovery key and reset the ICloud password it will changing successfully but that issue will be the same