If Alamo gave you a lower-class car than what you reserved, keep everything: the booking confirmation that shows the class you reserved, information about the real car, and photos in case you need them.
Bring it up right away at the rental booth or within 24 hours to Alamo Customer Support so they can change the price or give you a good replacement.
Ask for either the price difference back or a free upgrade or credit for a future hire when you call them.
If they don't give you money, write to Alamo's Damage Recovery Unit or area customer relations office and ask them to help.
If they don't, consider filing a complaint on Xolvie to seek a resolution.
Related Complaints
I Was Refused My Reserved Car by Alamo Rent A Car at Hanover Airport

We landed in Hanover on May 8, 2025, having rented a car from Alamo Rent A Car a few days prior through Carflexi, with ₺900 already blocked on our credit card. When we went to pick up the car at the airport, there was only one woman working at the Alamo counter. She refused to give us the reserved v...