Maybe I’m misunderstanding, but should there be an adjustment credit instead of a debit so the account balance will be zeroed out? Or do you use a negative number for the debit?
Example: Customer owes $1.00 and we’re writing it off. We pull up the customer’s billing tab, go to transactions, then hit “adjustment.” I select my “bad debt” debit for the service and enter 1.00 in the amount. I submit and now the customer shows as owing $2.00.