I'd love to take it to another shop, but the car doesn't seem safe to drive. I might have to figure out a tow truck to bring the car to a different dealership or something so I can at least get evidence there really is something else wrong besides the injectors.
Adding to the story, when I went to pick it up, they were pretty shady about it (plus terrible customer service attitude, despite them being the ones who told me it was ready and it clearly wasn't). It seemed like they either wanted me to just pay for the
spark plugs and take the car away, or sell them the car at that laughable price.