Correct. Once your return is transmitted to the IRS, the only thing you can do is try and cancel the payment, by calling the IRS, assuming you can reach a human being. To prevent fraud, the IRS will not accept verbal or written instructions to change the payment account or payment method, the only thing you can do is cancel the payment. Then you would make your own payment arrangements by mailing a check or making an electronic payment at www.irs.gov/payments.
