If you are using TurboTax Online Free, you don’t have to pay to file, you just need to confirm the order. After you confirm your order, it shouldn’t take you back to the start of the return. If it does, you can get back get back to the filling section by selecting “Get Started” under the “File” tab. If it still is not working, please try clearing your browser cache, or use a different web browser. https://turbotax.community.intuit.ca/replies/2647843
If you want to upgrade your return, you can click on the “Upgrade” link under the Refund/Balance Due. If you start a new return, either through the Return Manager (under Tools) or through our product page, you can select a different level of TurboTax, but then you would end up with a new, empty return.
If you can’t find your original return, this link may help: https://turbotax.community.intuit.ca/replies/2648026