My payment was rejected though my returns were accepted. Help!

not to worry you have until 5/17/2021 to pay.  i strongly recommend using the IRS website to set up an electronic payment.  the only reasons I can think that you couldn't succeed using TurboTax was a bad routing number - 9 digits, a bad account number  - don't include check number which usually comes after several special characters on checks and don't use a/c number on deposit ticket since they will sometimes differ from the a/c number on the check (best to use whatever a/c number appears on bank statement) or insufficient funds.   

https://www.irs.gov/payments 

your choice

checking or savings a/c (free)

credit or debit card (a fee may apply)