Doubt that you can get the Ford dealership that sold you the truck to redo its sales prep work for free. You bought it that way, and you own it that way. You'll pay for the service, I'd bet on it. Fortunately, the plugs aren't difficult to get to and you can do the work yourself.
However, check the spark plug specification on the emission control sticker under the hood. If they installed a plug not specified, I highly recommend that you replace all 16 plugs with the plug specified by the factory. Here's why...
Before I owned my Raptor I owned a GMC Canyon. At 60K miles I did a plug swap, and bought expensive Bosch plugs that were listed as an equivalent replacement for the factory plugs. In a matter of just a hundred miles or so, the truck threw codes indicating an ignition system problem. I went back to the auto parts store that sold me the Bosch plugs, and was told that this happens all the time now with aftermarket plugs. The explanation is that the software that manages all of the systems in a modern vehicle is written with the characteristics of the factory specified spark plugs as a prime factor. Aftermarket plugs can introduce sufficiently different characteristics into the mix and cause the vehicle to throw codes. They apologized for their mistake in selling me the wrong plugs, gave me the factory specified plugs, and refunded my money for the Bosch plugs.
As a result of this experience, my recommendation to you is to buy 16 of the factory specified spark plugs, gap them properly, and install them yourself.