I accidentally clicked deluxe instead of basic to get my 2017 tax return and I'm not going to pay $60 for it, since I have not used a single feature of deluxe.How to fix?

If you have not paid for the online edition you are using, have not filed your tax return or registered the Free edition, then you can clear your return and start over with a lower priced edition.  Click on Tax Tools on the left side of the program screen while working on the 2017 online tax return.  Click on Clear & Start Over.