Debit note is not avail able how to return good and receive back cash
Is this really needed? I mean Credit notes are useful because you need to print them and give them to customers. You are not giving supplier anything, he should give you credit note and then refund you. When he refunds you, simply enter the refund as received money in bank/cash account and categorize this transactions as Purchases (or other expense account so this will offset the original purchase amount)