My guess is that your Dealership needed the trailer drawers to sell, or possible cover another trailer's warranty issue, so they robbed yours in hopes of replacing them before they sold the unit. You and the DW came in before they could replace them so they made up that story they told you to save face.
As others have said, hold their feet to the fire and have the Dealer replace the drawers before you take delivery.
2019 Jay Flight 264BHW, Rocky Mountain Ed.
2020 Ford F150 XLT SuperCrew, 3.5L EcoBoost w/Turbo