Hi, 

In order for us to understand your scenario correctly, it’s best to call Sage 300 support at 800-253-1372 to confirm this is your scenario before making any further adjustments. 

If you want to try to make adjustments, please make a backup of your data before you try the suggestions below.

Have you tried to create an A/R adjustment to increase the A/R invoice back to the original amount for the next period (using the Credit amounts)?  Then, use an A/R credit note to apply against the AR invoice to cancel the invoice in the next period? 

If your debit note is still outstanding, create an A/R credit note for the current period to cancel it out. 

Also create the new A/R invoice in the correct period if you need to after everything is cancelled. 

Hope this helps. 

Regards,

Wendy 
Sage 300 support