Customer payment through QuickBooks was accepted then returned. I voided it, they paid via another channel

We'll have to record the invoice payment manually instead, John289. Let me help you with recording the transaction.

You can follow these steps:

1. Click the New button.
2. Go to Receive payment.
3. Select the customer, then the invoice.
4. Under the Payment method, you can add or select the method you were paid by your customer.
5. Enter the amount received.
6. Select where you'll deposit the payment.
7. Click Save and close. 

I'll include this article to better guide you with recording the transaction: Record invoice payments in QuickBooks Online.

Feel free to reach out to us again if you have other concerns. We'll be around to help you out. Keep safe!