If you haven't filed you can just leave and abandon it. You can try to clear it.
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-onli...
You can not delete or merge accounts.
You can try to clear all of the information in your TurboTax account for this year but you will need to Contact Customer Support to have an account deactivated for more of a resolution.
Intuit - How to delete my account
How do I delete my account? | IRS Free File Program delivered by TurboTax
