I'm not quite sure I understand what you are after. If a form is published as a content type, then users can create new forms in the form library. Each form will have different data. Some forms may have similar data. Your form template should have a rule that ensures that each form has its individual form name, so nothing gets overwritten.
A form library is meant to have many forms created from the same template.
If that is not what you are after, please edit your question and explain your requirements.
I can then amend this answer.
Edit after more information was provided:
Set up a rule that gets triggered when the company name is filled in. Look up if a document with that name (Company - Network Information) already exists. If it does, switch to a view where the user sees a message like "This form already exists. Please edit the existing form."
For the lookup you may want to set up a secondary data source to your document library, so you can query that data connection without disturbing the main data connection. Set the query parameter to the name of the form, then query the data connection. Count how many items are returned. If it is 0, the form does not exist.
Second edit: How to create the rule (rough guideline, off the top of my head)
- You need to set up the secondary data connection to the main data source, and select the file name as one of the fields.
- Trigger the rule when the company name is changed -- set the rule on the company field "when the field changes"
- Action: Set the query field of the secondary data connection to the same value that you would use for the file name of a new form, e.g. the company name concatenated with the text " - Network Information.xsn".
- Action: Query the secondary data source. The secondary data source now contains all items that have the same file name as what you put into the query field. If a company form already exists, that should be one item. If the company form does not exist, she secondary data source should be empty.
- Create another rule that triggers if a count of the secondary data source is greater than 0.
- Action: Switch to a different view that shows a message for the user and a button that closes the form without saving.