TurboTax failed to file my taxes from 2014. I now have interest due and didn't know until yesterday. How can this happen and what is my recourse with TurboTax?

[Critter]

TT doesn't file your return, it is a DIY tool and not a tax prep company  ... only you can do that in the FILE tab. You had to transmit the return and check to see if it was accepted or rejected.  If the return was rejected you had to fix the error and resubmit the return ... and email would have been sent out to alert you to the rejection and instructions on how to correct the situation. 

All you can do now is print, sign & mail the return.