This really sucks, as I am seriously considering one of these. Along with some of the issues I've come across in my research, this is another potentially expensive issue that may add up to really high long term costs.
If you keep getting no-where with Dodge, contact the FTC. Under the Magnuson-Moss warranty act, which is governed by the FTC, it doesn't matter who did the oil change. Per the act, you should be covered since the dealer (using your vin as stated) gave you the wrong oil; you didn't go buy this yourself at a parts house. I would bet cash that dealer techs have done the same thing. You have the documentation, and I'm guessing the parts guy just grabbed whatever diesel oil was closest instead of confirming what was required. This is no different than a tech using the wrong fluid in the transmission, which just happened to my cousin; just took his 14 Charger in for a trans service (fluid and filter) and it died pretty horribly soon after. He suspects they may have used +3, since this dealer services a ton of older Mopars.
A key point is not to give up and don't take no for an answer; it took my dad a while to get his issues resolved, but wound up with full replacement value for the truck and all costs and fees associated with the action, including loss of the truck and a portion of the costs of the replacement truck. Dealer was an absolute nightmare to deal with, and the representative at the hearing made the mistake of being overly arrogant towards the judge; didn't take 20 minutes to slam the dealer with every expense the judge was allowed to levy and then some.