quantity

Hi,
I know that it’s not possible to save a negative quantity order in woocommerce and I know also the possibility to work with refunds.

For a special product (Pfand – bottle deposit) I need the possibility to save a negative quantity order. If the customer bring back empty bottle. I Will make an order with the product „credit for return bottle“. The amount of this product should be negativ e.g. – 6. This is necessary for the verification of the „return bottle“ process. I am using the amounts of the product „delivered bottle“ and „returned bottle“ in a sql query to monitor the process.

How can I do this with woocommerce?

Best regards
Siegfried