Thanks! The dealership sounds like a good one. Everything you've said about conversing with them and their response is blameless. They're just as much a victim of this defective vehicle as you are! Nobody wants this crap to happen.
Now, Kia Corp. sends out techs to examine these rare fubar incidents. As a poster above shared, it can take months (six months or even more). I'd say that 24 days must feel like a powerfully long time already! But you're just going to have to be patient with how long it takes Kia to work through this.
Meanwhile, I agree with your original decision to not take this vehicle back. Try and obtain a replacement. And let Kia do the autopsy on your dead Stinger and deal with it. It's their problem now, not yours. In fact, I would not even refer to it anymore as "my car". "Your car" hasn't been given to you yet. Insist on this as often and firmly as necessary. It looks like UT's lemon law is yours to wield. But heck, Kia should bend over backwards to get you into a brand new Stinger. Good luck!