Q:

I recently rented a car through Payless Car Rental. When I arrived, there was a long line. I noticed that people were leaving unhappy, but I decided to stay positive.

I needed a navigation system for my trip, but the price to rent one, $11 a day, was the same amount I paid for the rental. I told the employee at the desk that I couldn't afford a GPS but that I needed one.

A manager was called and I explained my concern - that I needed a GPS. He agreed to give me the GPS at no additional charge. I did not agree to pay extra for it in the contract I signed. They gave me a receipt, too.

Before I left, I asked again, "Am I going to be charged for this?" I was told no. Before I left, I asked again whether I was going to be charged. Again, a manager said, "Don't worry. Everything is taken care of. You are not going to be charged."

My credit card has been charged.

I've called multiple times to ask why I've been charged. The company opened a case and the final answer is: no refund. I would like my $187 back, please.

- Mihaela Sturm, Grand Marais, Minn.

A: If Payless told you you didn't have to pay for your GPS, you shouldn't have paid for your GPS.

But before we get to your navigation system, let's talk about pricing. Your rental car was a bargain at less than $10 a day. The GPS, at $11 a day, was not a deal. Payless has embraced an airline pricing model, where it offers an attractive "base" price and then adds on fees that can make your rental more expensive than a full-service car rental agency vehicle.

I'm not a fan of that kind of pricing because it gives you the impression the car rental is cheap, when it is often not. If you want to do something like fill the tank with gas or add a car seat, you're suddenly paying twice as much for your wheels. Tricky, isn't it?

Some people claim this is the free market at its finest - that you have a choice when it comes to GPS or renting a toll transponder. If you bring your own, you can save money, and the car rental company gets to advertise a really low, and bookable, rate. But look at your situation. You needed a navigation system and Payless made you pay more for it. A lot more.

Making matters even worse: A representative told you that you wouldn't get charged for the GPS. Then they turned around and charged you. Come on.

To avoid something like this, you should always get the offer in writing. I asked for your paper trail and you showed me a receipt that said you wouldn't be charged for a GPS. That's a slam-dunk case if I've ever seen one. A brief, polite appeal to an executive at Payless would have done the trick if the company didn't agree to what it already had agreed to in writing and orally. I list the names, numbers and email addresses on my advocacy site: http://elliott.org/company-contacts/payless-car-rental/

This case has an unusual resolution. I asked you whether I could review the correspondence between you and Payless. You said you hadn't yet emailed the company, so you did. Payless agreed to refund the $187, minus a hefty $50 cancellation fee. Although I felt the fee was high and was willing to ask Payless to waive the charge, you indicated you were happy to get some of the money back and decided to let it go.

I'm happy that Payless finally kept its word - more or less.

Christopher Elliott's latest book is "How to Be the World's Smartest Traveler" (National Geographic). You can get real-time answers to any consumer question on his new forum, elliott.org/forum, or by emailing him at chris@elliott.org.