You are correct, there is absolutely no charge with absolute zero.
You may have added the PLUS benefits which is an optional add-onpackage.
If you have not already paid for the benefits use the link provided to remove PLUS.
https://ttlc.intuit.com/questions/2583649-can-i-remove-plus
If you have already paid for PLUS, there is no way to refund your order; however, here is some exciting information on the Benefits that you have!
https://ttlc.intuit.com/questions/2583650-what-is-plus
You can also contact TurboTax customer service with the link below
https://ttlc.intuit.com/questions/3401489