Help please

I would really appreciate some help and acknowledgement as I have asked this previously with no response.
I recentlye placed a form on my site that I know several clients have filled in.
These forms are not showing under my submissions tab and I can’t see any sign of them anywhere, there a few submissions that are completely blank.
This is extremely frustrating as i really do not wish to go back to my clients and ask them to resubmit.
Why would this happen? Can I retrieve this data anywhere?

I am just about to uninstall and find a plugin that actually works!

https://wordpress.org/plugins/custom-registration-form-builder-with-submission-manager/