Obviously, bad.
My point was: Given that Infuse 7 was released two years ago, it wasn’t likely you paid for Infuse 6 only a year ago; and regardless, Firecore didn’t break any promises because they upgraded every Infuse 6 subscriber for free as soon as Infuse 7 came out.
If you purchased Infuse 6 with a lifetime license, you’ve also purchased Infuse 7, Infuse 8, Infuse 9, etc. You should contact Firecore if unable to upgrade.
If you simply purchased 6 Pro, you didn’t purchase a lifetime license … but Firecore did offer you a free year of 7 Pro.
You can see which version you purchased by looking at your purchase history in the App Store, and you can also download Infuse 6 from there.
Infuse 6 if no longer in the regular App Store because it is obsolete.