TurboTax accounts cannot be deleted. You can ignore the emails just like you must often ignore other unwanted emails. Or you can try changing the settings for the email you receive:
Unsubscribe from TT emails
https://data-privacy.app.intuit.com/preferences
Once you have used TT to actually file a return, I believe it is not possible to delete it. I can't say that exceptions are never made, you would have to call customer support. Customer support can also "lock" an account as a security measure, so that not even you can log in without calling support and faxing or emailing proof of identity to the security team.
If it's just the emails, you can unsubscribe.
Intuit - How to delete my account
How do I delete my account? | IRS Free File Program delivered by TurboTax
You need to call me first thing in the morning cause I can’t get this to work. I’m getting frustrated if I can’t and you can see it and I can’t why can’t you load the thing for me like I’m telling you before you don’t do this, I will be contacting my lawyer to file a class action suit against you
You have added on to an old post. What are you trying to do? Sorry no one can call you. How to contact Turbo Tax
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-contact-turbotax/00/26991