Try using a 0 (zero) for the 2018 AGI.
If that is also rejected you will have to print and mail your tax returns.
Contact TurboTax support for canceling your state e-file fee paid by credit card. Use the key words billing issues when completing the problem section on the contact website.
Use this website to contact TurboTax support during business hours - https://support.turbotax.intuit.com/contact/
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
