Sorry to hear that JLRNA was not involved, but not surprised. Again, I'd look at the lemon laws in your state and have that information handy when talking to JLRNA as it appears you have an easy case (not that you want to go that route). As well, the dealer clearly is not "going up the ladder" with your problems, and I'd question any and all of their responses...If you haven't already, I'd make sure you get EVERYTHING in writing, who cares what they "think" is wrong or who they "say" they talked to....documentation, documentation, documentation, verbal conversations are meaningless in getting your issue resolved at this point. Your SA and I'd even wager that tech have no real idea what to do, nor do they really care..if they're just "telling" you what they think is wrong than they are guessing and I'd question that they are doing anything....work orders, parts orders, you want it all in hand and can then forward it as needed....
Obviously you want the issue resolved, but I'd also be asking for some "love" for dealing with all of this once it is fixed...if you own this truck and are keeping it, a nice extended warranty can smooth some frayed nerves. In my industry when we have a customer (typically it's his attorney) who "no longer has any confidence or trust" in the product I know what papers are coming and work to get the issue resolved by the MFG if at all possible.