credit memo in AR through Property Module in 12.1.3

We are using property module in Oracle ebs to create leases and billing lines. We export the same to AR to create invoices.

In many cases, after few months of original invoice creation, customer and client negotiate and want to ammend billing amount or cancel lease. For this a -ve billing line is created in Property.

When exported to AR, it does not create credit memo, but an invoice with -ve line.

This causes an issue as now client has to create a manual credit memo to knock off the invoices. Also, dffs have to manually copied for credit memo for reporting needs.