This is a disappointing story to read about here, as we got a new Trane system in July 2020. As an owner of an XL16i condenser and S9V2 furnace (from memory?), I'm actually not surprised. Hopefully the OP will get this thing fixed soon.
For me, the previous Bryant system came with the house and I used it 2002-2019 so I suppose nothing to complain about. AC broke 2019, and we didn't fix it until July 2020, during the pandemic making it a little more unpleasant.
When we shopped around for the system, I had found a yellow pages from 2002, in the attic. There were only 2 out of maybe 30 HVAC cos. in the book that still existed. We happened to go with 1 of the 2. Not really by choice, it happened that way when shopping and getting quotes. It's a racket. Just look on YouTube.
Buying HVAC is like buying a car. I had read online that if one got 5 quotes, they do not want the lowest quote apples to apples. They want the best installer, for a price as close to the lowest quote. Example, one trick they use to get a lower quote is to eliminate the stainless steel chimney liner, that's over $1k and maybe up to $2k. A reputable installer will not do that to save you money. If you want a high efficiency furnace they will tell you that's not an option. A cheesy installer will cut that corner and give you a lower quote.
At any rate I had already seen some of these stories online so I went into it figuring my warranty is only as good as the installer (seems reputable ones also will not give a lower price by eliminating an included extended warranty by them). The reason is say the system gets installed, and day 2 there is a leak. I have read that could be easily $1500 UNDER FACTORY WARRANTY.
I found that the most reputable cos do what I see at work on big jobs--there's one price all inclusive and it's not actually broken out. So our quote included the stainless steel liner and a 10 year extended warranty from the HVAC co themselves. Of course, worthless if they go out of business, but they were established 1971.
At the end of the day, the reputable installer ends of doing the job for about the same as the cheapest one, with everything included that the cheapest cut out. Very unpleasant shopping for this stuff. Once again didn't do Costco, assumed it would be more expensive.