I did back out of the "premium service" page and paid by CC. I just got off the phone requesting a $10 refund of the credit that the TurboTax billing page was still showing on Oct 15. It's perfectly OK to have a credit expire, but NOT OK to keep showing it 6 months later then not honor it. Hopefully the bug will be fixed next year; I also requested that TT follow up with me in order to fix the problem -- it's a pretty simple line of code: "if (current date) is later than (expiration of discount date)=credit not shown on billing page.
TT had +160 days to fix that. If it's still a problem NEXT year, then it starts to look deliberately trying to mislead people. Interestingly, when I had gone to the billing page for the "Premium Service" of having my $25 state filing fee deducted from my refund there WAS a $10 credit. I don't quite know what was going on there--maybe someone in marketing had the bright idea of extending $10 credit for customers who "upgraded" to the so-called "Premium Service" in order to entice them to spend an extra $35 for a service that probably costs TT <$1. Like many ideas, great business idea if you write the code correctly; potential class-action lawsuit if you write the code wrong. Splash it as a "bonus credit" for club purchasers who file for "premium" and it's no problem at all. Falsely show a credit that you won't honor for credit-card-paying e-filers, and it's kind of illegal.
