Glad you are on the road. Im not surprised at all about your experience. These roadside assistance insurance companies just want to tow you the shortest distance possible but they are clueless about actual mechanics so they will go through a dozen shops if they have to, starting with the closest one.
They dont care about what you are going through and these small shops all enthusiastically accept the job and state that they can fix anything because they want the business and its no skin of their whatevers if they cant fix it. And no surprise about Cummins either. They may have the expertise but not an ounce of concern. I’m surprised they even agreed to help.
I will say the folks at Velocity do seem to truly care, they will try to put you at the front of the line if you are on the road, they have qualified techs, and can fix about any chassis issue you might have. Also their labor rates are about 40% less than Cummins shops.
Glad it was something simple and that you are back on the road. Hope it wasn't too unpleasant. I always learn from these stories so thanks for sharing.