Thanks so much for the information. With more research (a call to the IRS did nothing), I found the following on the IRS.gov website: "Call IRS e-file Payment Services 24/7 at [phone number removed] to inquire about or cancel your payment, but please wait 7 to 10 days after your return was accepted before calling." You also need to cancel or change the amount at least 2 days prior to the date of the scheduled withdrawal.
The call to the IRS had them redirecting me to Turbotax, which did not sound correct since the direct withdrawal information was on the 1040 - which led me on a wild goose chase until I did a search of the IRS website for the direct withdrawal cancel/change.
Calling the 888 number, I was able to easily cancel my original electronic transfer and then I set up a corrected one to be pulled on the 15th of this month through the direct pay site.
Maybe this info will help others in the same situation.
