Hi scoreincoutsourc,
Welcome to the community. I'm happy to help.
For you to know what these payments are, you'll need to pull up the QuickBooks report downloads from Authorize.net. If they were imported directly to an account (example: Undeposited Funds, or a specific bank account), open that account in QuickBooks. Select a transaction then delete the payments one at a time. We currently don't have an option to delete them by batch.
We're always here to help you. Just post your questions.