This is actually a review of Hertz location at Marion, IL and I'm putting it here as St Louis is the closest location listed here.

I made a reservation with Hertz at the above mentioned airport. The location was closed upon my arrival - one hour prior to their regular closing hour. Called the Hertz corporate office which couldn't help, had no clue about the whole situation, couldn't contact the manager/employees and in the end sent me back to the local manager (on the next day, of course, after I rented a car from Enterprise) who was avoiding any contact with me (was "with the client" all the time and never called me back). The corporate hotline is not helpful at all - I was told I even cannot place a complaint as their phone system was broken and later told me I have to complain to the local manager. Great service indeed!