You can view deleted WhatsApp messages as the following steps.
1. Connect your iPhone to your computer.
2. Install and run “iTunes” software on your computer, click the iPhone icon at the top left corner, choose “This computer”, click “Back Up Now” button on the right and then click “Don’t Back Up Apps” on the pop-up window. Back-up would export all data (including WhatsApp Messages database and attachments) in the iPhone to computer and thus it would take quite long time. When the progress bar on the window title bar disappear, back-up of iPhone is finished. Back-up would take unequal time from more than several minutes to several hours.
Pay Attention: Don’t check “Encrypt iPhone backup” box.
3. Install and run “Cok Free iTunes Backup Extractor” software, and then double click the backup file row.
4. Enter into var/mobile/Applications/, select folder group.net.whatsapp.WhatsApp.share” and then click “export” button to export this folder to your computer.
5. And then please select “net.whatsapp.WhatsApp” and click “Export” button to export this folder to your computer. All the WhatsApp attachments are saved in this folder.
6. open “Cok WhatsApp Recovery” software, set the WhatsApp type as “iPhone” and data path as the folder group.net.whatsapp.WhatsApp.shared” folder that is exported from iPhone backup, and set Resource path as the folder “net.whatsapp.WhatsApp” folder that is exported from iPhone backup. Then please click OK button.
7. Now all the WhatsApp messages (including some deleted messages) are shown on the software interface.