Get your taxes done using TurboTax

As stated - You must have entered something that the Free online edition does not support.  That is why the upgrade to Deluxe was required.

You did not have to accept the upgrade nor have to pay for the online account in the File section of the program.

You could have cleared the return and started over with the Free edition or you could have declined to use TurboTax before paying for the account.  That was your choice.