Unfortunately, the rental car companies decide this. Sometimes, locations can designate vehicles, away from what corporate had them classified as. There's no governing body on it, so it's up to the renter to accept whatever they decide is "compact", "intermediate", "full size", "premium", etc. This causes issues in the US, and you're not alone with being disappointed in how they classify vehicles.


The best way to handle this was BEFORE pulling off of the lot. Once you return the car, you're not likely to get much but *maybe* a good-will gesture of $$ off toward a future rental. If you ask before pulling off of the lot, they'll usually offer you other vehicles in the same class. Depending on the agency, they might have offered others that they consider intermediate (Corolla, Cruze, Civic, Elantra, Sentra, Forte, etc).