My federal payment was taken twice

For starters, when you owe money to any taxing authority, TurboTax does not, can not, and will not act as a middle man in that transaction.

More than likely what you did was give the IRS permission to withdraw what you owe, on your actual 1040 tax return form. Then after you filed it, you went online to www.irs.gov/payments and manually paid your debt to the IRS. So in effect, you paid twice.

Generally, the IRS will catch this 6-12 weeks after the fact and mail you a check to the address listed on your most recently filed tax return. But with the pandemic going on, who knows how long that will take, or if it will even happen that way?

I suggest you call the IRS at 1-800-829-1040 to inquire and expect to be on hold for a "LOOOOOOONG" time. Note that since the tax filing season ended on July 15, 2020, they will only be open M-F and I have no idea what their hours will be (due to the pandemic) or if you will ever be able to actually get a living, breathing human on the phone that can assist you.

But the bottom line is, there is nothing that TurboTax or anyone in this forum can do about it.

You might want to check your IRS account to see if you were credited for both payments.  You can check your IRS account here:

https://www.irs.gov/payments/view-your-tax-account