Unfortunately, once a posting/bill has been reversed this will have to be posted back onto the system as a new posting/bill eg (SIB).
This can be done through General Postings or Slips.
From the Main Menu open General Postings.
Select SIB posting type, click NEW.
Fill in the relevant details and date needed, bill number can be amended to the old bill number if needed.
Select the Floppy Disk symbol to save.
Select POST.