Is there a way to give a customer a credit memo without including any inventory items in the "lines" section? One of our salesman price gauged a customer, the customer found out, and now we need to give them a credit to cover the extra price that was charged. Basically what needs to happen is a credit memo that is linked to our revenue account rather than inventory since there was no inventory returned. When I go into invoice data entry, it won't let me give them any sort of CM without putting an inventory item on the lines. 

Is there any way to just add a CM for them without crediting and redoing the entire invoice? We use Sage 100

I'd appreciate any help! Thanks!