Recalculating discount on total price after returning products
I work at a payment company and we host payment methods for e-commerce webshops. We are soon connecting a new Merchant but we are encountering a problem which I cannot awnser. Here is the situation:
Magento 1 webshop uses a lot of discounts on the total value of the cart (let's say 4 items which all get a discount of 10% because they have a minimum off x products in the cart, and if you have 3 products you get a total of 8% discount on the total value). After the customer has received it's products, the customer sends 1 item back, there for the total amount of discount value should be recalculated.
My question is: does Magento have a function that automaticly recalculates the total value of the discount on the order after the Merchant deletes a product from the order.