I can see how you might be frustrated by your recent dealership repair experience OP. Your car only has 40K on it as I recall, so that’s almost a new car. But it is 6 years old, and problems do occur with time also, so you have to take that into account as part of the perspective.
I had a similar experience years ago, and that was the singular motivation I needed to take that adult auto repair night class I mentioned above. In my case, like yours, a dealership shop was the culprit. Someone in the shop made an error working on my car, an error that anyone could make when doing complicated wiring. The problem was, someone or some group of the staff there wouldn’t own up to their wiring error. I’m ok if a shop makes a mistake, especially if it occurs on something complicated like wiring. But I’m not ok if they refuse to admit they did it. So, well, that’s how I got to here …
In your case I think you’ve just had a run of bad luck. Most people are like you, they simply don’t have time to learn how to service their own car. And even if they knew, they don’t have time, space, equipment, and tools required to do it safely. About the only advice I can give you is that a dealership isn’t usually the best place to get service for a 2009 model. The reason is the staff there at the dealership is geared to providing warranty service, and that’s going to be occurring mostly on 2012 and newer cars. So dealership shops are all trained, tooled, equipped, and ready to service 2012-2015 model years. Not so much on cars older than that, like your 2009.
Suggest to take some time to ask friends, co-workers, fellow church-goers, anybody you have a trusted personal relationship with, who it is they use to service their car. From among that list, choose a shop that specialized in Toyotas or at least Asian cars. And be sure to tell the shop owner who it was that recommended you to them. That gives you an edge, b/c the shop owner knows if you are dissatisfied w/some service they provide, you’ll tell your friend about the negative experience you got, and both customers will likely be lost to a competitor.
If you’d like to get a start at understanding the basics of how cars work, and how to repair and service them, is what @db4690 says above (thanks for the nice complement btw db ) , that the key is to understand how that system is supposed to function; i.e. when it is functioning correctly. For that, a good book to have on your shelf at home is published by Popular Mechanics, titled “Popular Mechanics Complete Car Care Manual”. It’s arranged in short sections, so you can browse through it 15 minutes at a time, no need to read it all at once.
Best of luck.