We ended up using our Controllers card for testing small $1 Transactions. We were able to reverse all transactions.
I now see that there is a “Testing Mode” checkbox on the Credit Card Configuration form.
Worth a try.
Field Help …
Testing Mode
Indicates whether you wish to test this credit card configuration before actually using it against your actual data. Select this check box to try out the configuration and review its results.
When selected, Sales Order Entry and Cash Receipts Entry display a warning message to inform you that the credit card configuration runs in testing mode.
When you are satisfied that the credit card configuration works correctly, clear this check box.