I'd dispute as service not delivered as advertised. For a car service, just like a rental agency, you should get the same or better class/year. If you had a hunch and asked to clarify in writing, it should be an easy win.
Reninds me of my biggest unwanted 'upgrade' I ordered a towncar for 3 before Uber was around (since I was so tired of vomit stained 15yr old taxis in New Orleans). I called to make sure it was just going to be a car. A 14 passenger stetch limo showed up. Kind of embarassing for 2 adults and an infant to be paraded to the airport in a stretch limo.