Assume a customer has completed an order and forgot to add some items to the order. He calls the store and tells a staff member to add the items to the order, which is totally doable in the administration.
But since I don't want staff to do any math or remember any numbers, I need to find a function in WooCommerce that will tell me what the balance on the existing order is, so I can finish the plugin I'm making, giving them the option to charge the remaining balance.
Is there a function or variable in WC_Order I have missed that will tell me what has been paid, and what the current total of the order is now.
PS. It is not an option to create a new order, as my client in this case is getting so many orders that they can barely keep up now, so increasing work load by making a new order is not possible.
Thanks a lot.