How to charge items w/Credit Memos

Hi,

I've got a credit memo made in BI and sent to AR with an amount of $40 usd. The original amount was $65. In Cash drawer I need to charge the difference, should I charge both items and item of $65 and credit memo of -$40 thus charging $25 or is there another way to do this? I tried to charge both items in the same cash drawer, in the deposit I put both items and got the amount I wanted but in GL the account entries are not right. The amount in cash account should be what I charged