Refunding Gift Certificates and Credit Slips

Future updates may include further options for the refunding of credit slips / gift certificates but for now the suggestion is to create a sales ticket with no items. For more clarity, it could include just a single line with a dummy Sku for zero dollars, but in the description lines you could add some comments.

Then apply the original store credit slip as a payment

At this point the sale would be over-paid.

You can then enter other (minus)payment entries, cash or credit card or company check (i.e. your company's check) to balance it out.