Sounds to me like you actually ordered the 2018 product instead of the 2017 product from the "past years product" page. But that's a moot point now. If you'll be using TTX to file your 2018 taxes, you can just leave well enough alone since you've paid for it already, and just get TTX 2017 from the past year's product page at https://turbotax.intuit.com/personal-taxes/past-years-products/
Otherwise, you have no choice but to call Customer Support, as nobody in this public user-to-user forum can really help you with this. To get the number for Customer Support go to https://support.turbotax.intuit.com/contact/ Select your product and then in the question box enter the word BILLING and click the Continue button.
Then fill out the information on that page and if necessary scroll down and click the "Get the Phone NUmber" button. Take note that you will not be provided a phone number when telephone support is closed. Support is open M-F from 5am-5pm *PACIFIC* time.