I checked Corporate Rent a Car's website. They listed no information about the car rental
terms and conditions of their
What you will want to do is carefully read through all the
check into the company policy for returning a car when the lot is closed. Many car rental companies do not allow after hours returns; the early return fee could be connected to that policy somehow. I know it's totally frustrating.... let's face it.. hardly anyone ever reads all the terms and conditions of their agreement before signing it (although it is recommended, and I'm sure your son will do so from now on).
Your son is perfectly within his rights to dispute the charges with Corporate rent a car. He should contact a manager from the company or their customer service department and state clearly why he feels the fee should not be paid. (ie. if the contract does not state such a policy or if, for example, he feels that he was not permitted or allowed enough time to fully read his contract before signing, or the terms and conditions provided by email were unclear or incomplete, if the vehicle was reserved on-line.) I hope this helps!
Pages from this site, relating to this topic:
Car Rental Contracts
After Hours Returns