Does your truck have a Canadian window sticker, if not you may need more from the dealer.
In my case, Sirius told me my 19 Laramie was a used vehicle in spite of the fact it was never registered and the paper trail was intact from the factory so they were only going to give me a 3 mo free trial. It took sometime on the phone with them on a Sunday morning with me talking to an agent in the Philippines interfacing with him talking to the folks in India to get it corrected.
Took about an hour but they got it sorted out. Tell them that you talked to the dealership again and the radio is OEM from the factory. Don't take it's the wrong radio from them, go up the chain. Be persistent.