HOW TO UNDO LINE PAIEMENT

souoik

Hello my friends, I am lucky to be among the members of this forum. I want to propose my problem and I would like to propose a solution, we have a specific development in the order sales and payment part, the truck is what the sales order page, and split into two parts, part line order sale and part line payment.when I received an advance on an order I validate this payment with a pre forma invoice, after a period the customer wants something but he will speak with other commercial knowing that there is already an order related to an advance, the commercial create an order also a payment as long as the customer have a receipt, which makes the payment doubling one exists and the other no, here i want to create a function that automatically makes the cancellation of payment and the pro forma invoice (here in reserve Item)
thank you