Invoice voided + refund receipt issued, now I've a messed up number that doesn't tally, please help

if it is any helpful, I can find the 50% "unapplied" payment moved into the "Trade & Other Receivables" chart of accounts. 

Hello there,

Voiding the invoice detached your original 50% payment, creating an Unapplied Payment (credit). When you issued the Refund Receipt, it was recorded as a separate cash outflow (debit), resulting in a negative balance.

Link these two transactions to reset the customer balance to zero.

Here's how:

1. Click the + New button and select Receive payment.
2. Choose the Customer from the drop-down menu.
3. Ensure the Payment date matches the date you issued the refund to keep your reports accurate.
4. Locate the Outstanding Transactions section, where you will find the Refund Receipt you created.
5. Click the checkbox Refund Receipt.
6. Scroll down to the Credits section, where you will see the original 50% Unapplied Payment. Tap the checkbox for that to apply it against the refund.
7. Confirm that the Amount received field at the top now shows 0.00, as you are simply offsetting two existing entries.
8. Finish by clicking Save and close at the bottom right.

After saving, the balance will be $0.00, and both the unapplied payment and the refund receipt in their transaction list will display a status of "closed."

The Community is always here if you need anything else.