I understand your frustration. Car dealers have a thousand-and-one dirty tricks to get your buck$ (mine "accidentally" 'forgot' to credit my earnest money depost at the closing.) And, don't get me started on the proffered "Super-Duper Diamond Finish Sealant with Ionic Dirt, Rain and Bug Repellant with Free, Assay-Guaranteed: 79% Nitrogen, Tire Inflation Fluid!"
However, you can still (for now, anyway) take the offered deal, walk away and keep looking, or look for a different vehicle entirely. As for somehow getting recompense for your wasted trip, what can you do...? Let others know on social media and user/owner review websites and forums, like you did here.