I have a CC payment that processed but was never deposited due to an account issue. I need to cancel that transaction.

Let me help you voiding or canceling a payment transaction, drakedevore.

If  the payment transaction has already batched, you will need to give your customer a refund. You can refund the whole amount or refund specific products, services, or fees. But please know that refunding payment transaction have fees.

You'll want to enter a refund for your credit card or an ACH payment for a sales receipt. Please follow the steps below on how to do this: 

1. Click + New.
2. Select Refund receipt.
3. Select the customer you want to refund from the Customer ▼ dropdown.
4. Fill out the fields using the same info from the original sale. To credit back their credit card, in Payment Method, choose QuickBooks Credit - Credit card. To credit back their bank account, in Payment Method, choose QuickBooks Credit - Bank.
5. In Refund From, choose which payment method and account you wish to refund the customer from.
6. Click Save and close.

To refund an invoice that the customer already paid:

1. Click + New.
2. Select Refund receipt.
3. Select the customer you want to refund from the Customer ▼ dropdown.
4. Fill out the fields using the info from the original sale.
5. Choose which payment method and account you wish to refund the customer from. Note: You can't refund an ACH payment to the customer’s bank account. You'll need to choose another refund method (cash, check, or store credit).
6. Click Save and close.

Moreover, let me share this resource on how to void or refund customer payments you process in QuickBooks Online. It also includes some ways how to give partial refunds. 

Additionally, you can verify when QuickBooks deposits your customer payments into your bank account. For detailed information, kindly check out this article:  Find out when QuickBooks Payments deposits customer payments.

Reach out to me if there's anything else I can help you with. I'll always be here to assist you. I look forward to hearing about your success.