Hi laurietal55,
An invoice in QBO can only be deleted by a user. I can help you check the audit history of your invoice and retrieve its details, so you can recreate it.
To start, you'll want to click on the Gear icon and choose Audit Log. Then, click the Filter drop-down list and filter the deleted transactions, like in the screenshot.

Once you get the list of deleted transactions, you'll want to click View on the deleted invoice log. Then, see who deleted it and expand creation details, so you can see the list of items, dates, etc.

Feel free to go back to this thread if you have other questions about your invoice. We're just around to assist you.