How to reverse the Purchase order after the item was consumed by production order?

Hi all,

I am using Dynamic AX 2009. I am having one problem.

I have one purchase order with the wrong unit price, user registered the item with using the wrong price but manage to detect the error before posting the purchase invoice. When i try to trace the item, it was issued to production for work order, all the production work orders were ended.

My question is now i cannot unregistered the item which is now 0 in inventory. But if i post the purchase invoice as it is, the final cost for the finished good will be extremely high.

Is there a way to resolve this issue?

Thank you in advance for helping.