I'd like to welcome @Tremper126 as a moderator on the forum. He'll be helping us out on the site to control the spam posts and help to maintain the posts/content on the forum.
Glad to have you on team!
Check this for the cord, https://www.ecodieselram.com/forum/threads/engine-block-heater.407/#post-2438
If yours doesn't have it, you can buy one from Amazon:
https://amzn.to/3gf12Dz
Welcome! Keep your warranty, maintain it, and treat it like it's your kid. Not all are bad, but it does have a lot higher failure rate that other diesel trucks.
What were they going to do to fix it for that much money? It looks like it needs a regen.. it sounds like this dealer is terrible. I'd highly recommend getting that truck somewhere else.