How does the user credit get used up?

Hi!
I’m New to the Directory Theme and trying to get along with it. So, I created a user, put some credit to the user. I have set my site to accept cash payments (mobile payments) so I use the Bank Payment Form payment gateway. This user then posted a listing on my site after purchasing a membership. I approved the listing and is now live. But if I look at the user’s profile, the credit(money) that I put for him is still intact, so I’m wondering why isn’t this credit being used up when the user creates a listing? Is there anything I’m not doing right?