Get your taxes done using TurboTax

I purchased TurboTax deluxe through Amazon.  I'm now trying to pay the $25.00 charge to e-file my California state return.  I chose the option to have my federal refund reduced by the $25.00 charge but in completing the transaction, it wants to charge me the $45.00 for the app as well.  How do I just do the $25.00 addition? mona