I have a Purchase Order with three items : Item A, Item B and Item C. I received the first bill 1 for the Item A, and then a credit memo for the same Item A. Then later I received a bill 2 for the three Items A, B and C. Logically the three items should still be available in the Purchase Order to bill against, but Netsuite took off the item A from the Purchase Order once I billed it and canceled the bill by the credit memo. How to resolve this issue and avoid it in the future?

Have you follow this process ? creating a new return authorization form; approving the return; shipping the return to your vendor; entering the corresponding credit or refund for the return from your vendor.

That’s a good question, I did not create a vendor return, the credit memo is created from the invoice, it’s like an invoice cancellation, but the item is still in our inventory and still payable by the new invoice. How to make the item appear again in the un-billed items?

as I told you in my message above..