Discover processed payment from closed bank account?

As the title says an automatic payment was pending from an account I closed a while ago so I payed my statement from my current bank account but yet both payments were processed and now it says I have 326 dollars in credit on my card. I thought the payment wouldn't get processed due to the account being closed but it did and it's posted so I'm waiting a couple days to see if discover notices and bounces the payment.