Why would I receive a tax refund from the US Treasury when I had owed and paid through TurboTax a large dollar amount in taxes?

You'll have to wait for the explanation letter in the USMail.

Thank you, Lisa995.

The IRS could have adjusted your return.  You will receive a letter or notice soon that should explain the deposit.  If you would like to verify your account information/transactions, you can use this link.  View Your IRS Account Information