A: Hertz and Auto Europe should be falling all over themselves to help you with a refund. If your Auto Europe confirmation said “INSURANCE OPTIONAL,” then the insurance should have been optional. Instead, Hertz hit you with a charge for CDW and “theft protection.” (What is that and why is it mandatory? Who knows?)

Worse, the car rental company had you over a barrel, since you’d prepaid for your car. I think car rental companies and their agents need a reality check. How the heck can you charge someone $213 for a rental and then $510 in “mandatory” insurance?

The paper trail of correspondence between you, Hertz and Auto Europe, your agent, is even more frustrating. At one point, it appears you’re in an online chat with Auto Europe. In one memorable exchange with Hertz, a representative declares, “Silvia, we are showing that the CDW and TP are mandatory in Germany unless you have a letter from your insurance company stating that rental cars in Germany are covered. Did you have this letter? All reservations with Dollar/Thrifty in Germany have this requirement.”

You ask why the requirement wasn’t disclosed. Then Hertz says, “The charges are valid.” Your reaction is priceless: “Am I talking to a bot?” It wouldn’t surprise me if you were. If Dollar, which is owned by Hertz, requires insurance and theft protection for its vehicles — and it’s well within its rights to do so — then it must say so. Upfront. Quoting $213 but charging $723 is wrong.

I publish the names, numbers and email addresses for the Hertz and Dollar customer-service executives on my consumer-advocacy site: www.elliott.org/company-contacts/hertz/. I also have the contact information for the Auto Europe executive contacts: www.elliott.org/company-contacts/auto-europe/.

I contacted Auto Europe about your case. The company agreed to refund your insurance charges.

Christopher Elliott is the ombudsman for National Geographic Traveler magazine and the author of “How to Be the World’s Smartest Traveler.” You can read more travel tips on his blog, elliott.org, or email him at chris@elliott.org.