All you can do is to keep trying...but I'm not sure what they can, or will do.
SO you've learned a hard lesson that many people need to keep in mind, and that is to come back into your tax file every week...AFTER you have filed, and keep checking to see what the status is...don't depend on an email notice from TTX (100's get mis-directed due either to people mis-entering them...or they get in their Junk folder and never notice.).
All you can do yourself now, is to print out your NC tax file, sign/date it and send it in by mail to get processed (along with any W-2 or any other tax form that shows NC withholding on it). Be sure to use a tracking method at the Post Office service counter.
IF you can't find the address....see the bottom of page 7 of the 2019 instructions:
And just paying the fees does not file the return. Did you continue on to the very end and actually file it? Was your federal filed and accepted? You can't file state until federal is accepted. Maybe you were supposed to mail it?
Maybe you didn't finish filing it or it Rejected. When you log into your account you should also see the status and if it was Accepted or Rejected, Started, Printed, Ready to Mail, etc. what does it say?
Then when you efile you get back 2 emails. The first email only confirms the transmission. The second email says if the IRS (or state) Accepte.d or Rejected your efile. Check back though your emails if you have them.