Dealers don't pull that bs. I don't care what people say, the ones who have bad experiences are typically assholes who don't know how to be patient and don't understand that these trucks are complex vehicles that often require some trial and error to really pinpoint an issue and get it fixed.
Dealers have two goals: sell you a car that you want at a price/value that works for you, and make you happy. That is it. There is minimal benefit to a dealership in jerking customers around whether it be with service or with sales. They want to win you as a customer for life... meaning you will come back to buy your next car from them, and you will always do your servicing and maintenance with them.
Give them time to get the issue fixed. Take it back and explain thoroughly what is going on. Offer to demonstrate, take a service tech for a ride, etc. Explain what you think it might possibly be. They are working in your best interest but can only do so much. Some issues take more time than others, but trust me, they aren't just trying to intentionally screw you until the warranty is up.
Source: I work for a dealership group at the corporate level. I know how these stores are managed and what the values are.