Since you filed your return using TurboTax last year and then imported your tax information from last year, then your tax information will carry on from the prior year.
To use the free version, you will have to clear and start over the return again. When you start, it will ask you if you would like to import information from prior year. On the prompt where it says that if prior year forms still apply for this year, you will have to say No. If you import the prior year return, and state that prior year forms still apply, it will assume you want to file 1099G again this year and will automatically upgrade you.
Please visit How to clear and start over on detailed instructions on how you can clear and start over.