2021 Kia Soul Turbo Engine Issues

It is with a heavy heart that I must report on the status of my 2021 Kia Soul Turbo. A few weeks ago it threw some codes and I took it to the dealer. It turns out that cylinder #3 needed to be replaced. It was covered under warranty so all was well although the dealer tried to say it wasn't under warranty which it was so luckily that worked out. I had the car back for a couple weeks and it randomly overheated on my drive to work. My commute is less than 20 mins and no highways. It was during that massive heat wave recently. I checked the coolant reservoir and it was basically empty. I bought some premixed coolant to top it off and all was well. A couple drives later it was empty, so obviously there's a leak in the reservoir or a crack in a hose. We were preparing to take it back to the dealer for the coolant issue when the engine light came back on with more codes. This time it was cylinder #2 and cylinder #3 as well as multiple cylinder misfires. We had to tow it to the dealer because when I cranked it up to move it to the other side of the driveway a puff of white smoke that smelled like burnt coolant came out and I wasn't going to drive it in that condition. We called Kia North America ahead of time and they said we could take it to a different dealer because we didn't like the experience at the first one. All was well until it wasn't. The service tech calls and says that my car needs a new engine and that it isn't covered by warranty because we've never done an oil change. Are you serious? We've done every oil change on schedule but not through the dealer network. We've used an independent mechanic and sometimes my husband does the oil changes. As a matter of fact the most recent oil change was at the first dealer we went to. Luckily we have all the receipts from everything that's ever been done for the maintenance on the car, but it's still a pisser having to prove it to get the warranty to cover it. The car will be 5 years old in November and only has 33,000 miles. I love my little turbo Soul but now I'm soured on Kia in general. I'm mostly venting here but also wondering if anyone has any experience going up against Kia when they are trying to deny warranty coverage. Oh, and they also tried to say that the coolant issue was just normal evaporation. Really Kia? It evaporates entirely after every few drives after almost 5 years of ownership? Uh huh, ok Kia.