Get your taxes done using TurboTax

It would seem logical that payment of the bill prior to the debit would cancel the debit  however whoever said the IRS was logical ... FYI this is the same thing that happens with other bills you set up on auto debit so be careful in the future. 

Sadly you did not read this entire screen in the program when you set up the payment ... now all you can do is wait for the IRS to refund the excess payment ... a painful lesson to learn. 

Review the screenshot below ... note where it says "to cancel payment" you need to call ....