Correct there is a Checkbook for the Credit Card processing machine - then they take that and record a 'transfer' from that bank to the 'CASH BANK' after the Credit Card processor takes their fees. Bit of a pain, but it works in the end.
So, the refund should have been to that Bank, and should have been recorded as CASH so that the dollar amount is shown as a reduction in the bank for the Credit Card.
Did I get that right?
I will look into the reason that the VOID is not 'acceptable'