Hertz said the mechanical key is "lost"
 

We rent a car from Hertz last weekend. After we returned the car and dropped off the key in the box, we got a phone call from Hertz the next day saying that they got the key fob but the mechanical key is missing. We never used the mechanical key in our trip and didn't even notice if there was a mechanical key when we picked up the car. The staff insisted that the mechanical key won't accidentally fall apart unless we manually pull it out. They have charged us $100 per day after we returned the car. And they never respond to our message or phone call after.

Am I liable for these charges? What would be the best course of action at this point in time? Especially we never use the mechanical key, we really don't understand how come it could get lost
Any help/advice would be very appreciated

The only way for you out of it may be to prove the key looked that way when you picked it up. Did you happen to take any videos or pictures of it in the rental facility at pick-up? But iIf they are making you pay for the key they should just charge you the flat fee for the key and not a recurring daily charge

It's impossible to prove a negative since nobody would take a picture of the key. If you are 100% certain that you didn't do anything with the key, I would reply to Hertz and say that you never did anything with it, and if they attempt to charge you for it, you will fight them over it (including BBB, arbitration, etc.). That might convince them to drop it, but you have to be willing to follow through if they don't.

Unfortunately, I agree with this. This reminds me that I need to check and photograph key as part of my pre rental and return photo/video ritual.

I rented a car from advantage a few years ago and I noticed the actual key was missing from the fob after I drove off the lot with the car. Luckily for me, they didn't try to charge me but I have to admit that I haven't been diligent about photographing and checking keys. I will do so on my next rental.

Assuming this wasn’t a joke….

How is it useful to take a photo of the snow/ice brush? If there is one and it isn’t broken, how will you use that photo?

I was under the impression that there are no spares in rentals usually? I haven't looked since I read that somewhere.

Sigh... whatever happened to humor...

How about the gas cap? Budget charged me after return for missing gas cap. Prepaid fuel, one-day rental didn't need to even open the fueling door returned on fumes...