I can't tell if you are asking because this is going to happen or has already happened.
If you have not yet received a refund, it will be reduced by the amount you owe. I don't know whether that will take into account a payment from the day before, but if the IRS does end up over-collecting, they will send a check for the difference.
If this has already happened, and your refund was reduced plus a payment was taken and you are now over-paid, the IRS will send a check for the overpayment.
