You are correct in that if you did not benefit on your federal tax return by deducting your state taxes that were later refunded, then they would not be taxable on your federal return in the following year.
TurboTax should have asked you questions to determine if your refund is taxable. It may be advantageous to go back through that routine to make sure you answered the questions accurately.
If you are sure your refund is not taxable, you can choose not to enter it as taxable in your TurboTax program.