I need to find WordPress plugin/plugins that does the following with Contact Form 7
Applies a Unique auto incrementing reference number to each form submission
Sends email to the admin of the website
Requires admin approval to add the completed contact form 7 to the Database
Records need to be editable in the backend of the website
Export individual records into a PDF
Customise the PDF with the logo of the business
I have some intermediate knowledge of PHP so I’m happy to extend plugins if need be.
There isn’t a plugin that modifies Contact Form 7 to meet all you want to do. I would suggest Formidable Forms (https://formidableforms.com/). There forms can have almost all the functionality that you require. Yes you’ll have to pay to get the things you need (https://formidableforms.com/pricing/#all-features) but this is really a custom form.
I know that doesn’t really answer your question but I’m afraid there isn’t a solution for it with Contact Form 7.