Can my computer be repaired?

I have a 2015 Mac book pro, 512gb, 2.9ghz, 16gb SDRAM. I bought it in July 2015. In December, I spilled water on the keyboard. I did everything right (after that crucial mistake, of course!): turned it off, turned it over, let it dry out, etc. After 2 days it wouldn't power on, so I took it to a local, 3rd party repair shop (which had good reviews, but was apparently sold a week or two before I brought my computer to them). Turns out it was the completely wrong place to take my computer, hence this post.

Long story somewhat short: They did a diagnostic test and told me it was the keyboard. They replaced the keyboard, but it still didn't work, and told me it was the power source. They replaced the power source and it still didn't work. Then, they spent several weeks trying to figure out what it was. They determined it was the logic board, and replaced that, but it still wouldn't boot. At this point they tell me that the SSD and the battery are also damaged (those have not been replaced). The whole thing has (obviously) become ludicrous, because what they are telling me is that the only thing not damaged is the retina display. Fortunately, because this has turned into such a debacle, I don't really owe them for much.

At this point I'm stumped with what to do (except get it back from this shop, clearly!). Do they actually know what they are doing? Is it normal that they weren't they able to see all the damage in the first place? Is there any way to salvage anything? I realize I probably sound clueless, but any help with what road to go down to get a working computer for as little money as possible would be greatly appreciated.