Issue: When an order is invoiced and a user needs to apply a credit to the order, current state the only options to apply a credit to an invoiced order is via an order credit or price match. If a user applies an order credit, a header level credit, at the time of processing a return against this order currently the user is seeing an over refunded amount. Furthermore, in the case of partial returns, current functionality does not prorate the order credit amount to the returned order lines therefore the user is refunding the original sales order amount.

Suggested idea:

1. Auto add the order credit to the return whether partial or full return- Similar to how price match is currently behaving, by automatically adding a charge on the return order to prevent the over refunding and having the charge visibility.
2. Prorate the order credit amount the sales order line in case of a partial or full return- in the event a partial return is needed the order credit amount would prorate to lines being return avoiding the over/under refunding to the customer.