Sorry to hear about your troubles, Webster.
Yeah, the factory mounted tires suck rocks.
Those are usually shipped to the factory very tightly banded to pallets which can damage the sidewalls of any tires that have the band cinched up against them. You and I both know that they are probably buying the cheapest tires they can get their hands on.
I'm afraid that your only relief may be to go the one tire at a time route until they find the culprit, which does leave the possibility of having another shipping damaged tire put on in place of the bad one or it could be an out of round rim but, balancing should fix that. There is still a whole laundry list of other items that can cause a noticeable vibration.
Do you feel it in the steering wheel or in the seat of your pants?
A good mechanic should move the tires one at a time and recheck to see if the vibration moves to narrow things down.
If all else fails, check your state for a Lemon law if you need to make more than four trips to the dealer and they still can't fix it, you may be able to force them to give you another truck and pass yours off to another sap... err...customer.