How to apply customer deposit to unlinked invoices at NETSUITE?

Hello, as per subject matters, the scenario is: Sales Order A was created. Later, we received customer's payment fully in advance. A customer deposit was therefore created on the said sales order level. Now, some items from this sales order have been cancelled due to customer has change minds, and these cancelled items have not yet been fulfilled or billed. The customer opt to use their payment made for those cancelled items to apply to their other overdue invoices which are unrelated to sales order A. However, when I attempted to "accept payment" for the unlinked overdue