OC2.3.0.2 Store Credit Error

Hi all, I am trying to use store credit in my online shop with OC 2.3.0.2. but some strange error happen.
If the customer have $200 credit and used $99 for placing a new order. The balance still $200 not $101 credit as wished for this order.
Any one have idea how to fix this problem?

Store credit is deducted when the order reaches a "Processing" or "Complete" status. You can set those in System > Settings > Option. Most likely, your order does not match one of those statuses, so the credit hasn't been deducted from the customer's account yet. Try changing the order status on your order to one of those statuses, and you should see it deduct.

Thanks Johnathan, make sense and all done!