Unfortunately you cannot delete or close your TurboTax account. However you can delete all returns from the account.

When you login to your account, click on the trash can icon next to a return to delete it.

If you only have one return, it won’t show the trash can. Click “Start a new return” to create a blank return. Now you should be able to delete your return, leaving only the empty return in the account.

Thank you for choosing TurboTax.

yes I am not familiar with the online version where one needs to photo all documents and submit that to the tax return helper .... therefor I want to cancel my request and ask for a refund ... thank you ..... R. S. (name edited for security on public forum)

To apply for a refund please see our TurboTax FAQ: How do I get a refund for a TurboTax product? If you purchased from a retail store, please choose From another retailer. 

Thank you for choosing TurboTax.