Best way to add Penalty and Interest for invoice in AR R12

Hello,

Could someone help me on how to add Penalties only once to the Invoice when the invoice is past the due date and Add Interest on a monthly basis to the invoice in AR R12 for the customer who failed to pay their Invoices on time?

I receive the data for Interest and Penalty from the Oracle Apex system on a regular basis,

I could use Debit Memo (DM) for adding them, but I could not link Invoice and DM together, which is causing difficulty for the collectors in the Advanced collections module to track all the DM related to a particular Invoice when they go for collections.