Question: I recently made a last-minute reservation on Hertz’s Web site and was offered a rate of less than $20 per day for a car. But when I checked in at the rental counter at San Francisco International Airport, the price on my rental contract was almost twice as much as the confirmed rate on my printout.

I mentioned the mistake and asked for a correction, at which point the rental agent tore up the contract. She said there must be a mistake associated with my travel code and that she would have to contact the corporate office.

After almost half an hour of calls and conferring with her manager, the agent handed me another contract. The rate on this second contract was the same as that on the first, but with a minor discount applied. The total cost was still much higher than what Hertz had quoted on its site.

After I pointed out this discrepancy and noted the total charges for the confirmed reservation, she tore up the new contract, made more calls to the corporate office, and attempted to contact her supervisor for help. Finally, I was given another contract containing the same higher rate as the first, but with enough discounts to the total rental charges to bring the cost down to match my confirmed reservation.

Is this what I have to look forward to every time I rent a car? Do I have to prepare myself for a 30-minute haggling session?

— Chris Chiang, San Francisco

Answer: No one should have to renegotiate a contract at the car rental counter, especially not with a car rental company like Hertz. Maybe if you’re dealing with Rent-A-Cheapo-Lemon. But Hertz has a reputation for being a cut above its competition — a reputation that is largely deserved.

Oddly, Hertz does not explicitly guarantee its online reservations, as far as I can tell. In fact, a look at the terms and conditions on its Web site suggests the opposite may be true. The company reserves the right to “change any descriptions or images of, or references to, any products or services on this Web site, or to limit the order quantity on any such product or service and/or refuse service to you,” according to the document.

Practically speaking, however, there’s an understanding that the car rental company will honor a reservation. Otherwise it just wouldn’t be able to do business. But it’s useful to know that if pushed — say, in a court of law — Hertz technically doesn’t have to honor the rate on your reservation.

In the unlikely event this ever happens to you again, don’t wait for the employee to solve the problem. Get on the phone with Hertz yourself and explain the situation. When the associate sees that you have absolutely no intention of accepting the higher rate, it may make things move a little faster. Don’t threaten to leave, however. At that point, the associate probably will want you out of the way, and you would just be doing everyone a big favor.

I asked Hertz to take a look at your case. When it pulled up your record, it found an error in the transmission of your rate information to the car rental location. “Nevertheless, once Mr. Chiang provided the paperwork with his confirmed rate, this should have immediately been applied to his rental without further incident,” said Paula Rivera, a spokeswoman for Hertz.

As a gesture of goodwill, Hertz refunded the entire cost of your rental.