I love my GMC. Great truck. But, and I'm being 100% honest with you, dealerships ANYWHERE are a major PIA. Colorado, then Utah a few years ago, and now a different one in Utah. They have some good people, and then they have some that aren't worth squat. That's normal for any dealership. And that hurts their image. But that hurts the customer more than the dealership.
I have been polite and respectful in complaining about these issues when I talk to GMC corporate. I have had audio and in one instance even video. I sent it, as directed by GMC, a written complaint with copies of the audio and video on CD.
And I never heard back. That was 2014.
Now, because I am not a mechanic, I pick the next best option in the town I'm in- a backyard witch doctor. I have no idea why GMC is like they are, but I bought the Jimmy because I love Jimmies. GMC is a great product. Customer service... (insert rolling eys icon)