Did you pay the TurboTax account fees with a credit card? If so, then the charge will be on your card statement.
See this TurboTax support FAQ for completing a 2018 tax return originally started with the online editions - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-started-in-turbotax-online/00/26322
If you paid for one of the TurboTax 2018 online editions then contact TurboTax support so they can push a 2018 installation file to your download account at no charge.
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