I submitted my federal return twice. NO refund received

[DoninGA]

Did you e-file your tax return and was it accepted?  

After completing the File section and e-filing your tax return you will receive two emails from TurboTax.  The first email when your tax return was transmitted and the second email when the tax return has either been accepted or rejected.

Use this TurboTax website to check the status of an e-filed return and if it was either accepted or rejected - <a rel="nofollow" target="_blank" href="https://turbotax.intuit.com/tax-tools/efile-status-lookup/">https://turbotax.intuit.com/tax-tools/ef...>
If accepted by the IRS use the federal tax refund website to check the refund status - <a rel="nofollow" target="_blank" href="https://www.irs.gov/refunds">https://www.irs.gov/refunds</a>

What is the status of the tax return/tax refund?

[DoninGA]

You cannot e-file the same tax return twice.  If the first return was accepted, the second return would be automatically rejected by the IRS.

[Anonymous]

if you paper filed the second return that can really mess things up and delay your refund.  

you can check refund status at IRS website.