Hi flex4u69,
Do all sales receipts and invoices come from Shopify? If yes, please reach out to their support team to get help in retracting the invoices or sales receipts. If not, you'll want to delete either these transactions to fix the duplicates. Also, please ask them on how you can avoid duplicate transactions in the future since you'll be importing data from their platform moving forward.
Please don't hesitate to reply below if you need anything else.