Hertz - never again
 

So I've also rented SIXT about 5 times in the past two years, never an issue. I've now also rented Hertz approx 5 times in the last two years, and also never had any issues, up to now.
Except the last time..... and this will be the last time ever.

I rented an Alfa Romeo Stelvio for 5 days on Hertz.com. Quote: 380€ with 1250 km's included and a fee of 69 cents / km in case I surpass the 1250 km. This is not a bad deal.
However.... 4 days after I return the car, Hertz calles me up to ask me if I actually returned the car! Sorry? Apparently they lost it in the parking lot.
Shortly after that I get the final bill: 600€
What happened:
they increased the rental price with 50€
they charged me 92 cents / km for additional km's
they added VAT on the entire bill (whereas it was included in the rental price according to the contract)
Needless to say: Hertz say they will not ammend the bill.

Thanks Hertz, this was the last time you saw me. Unfortunately, they're one of the stronger FlyingBlue partners.... but I'll now just shift my future car rentals fully to SIXT.

This has a pretty simple fix. Let your credit card issuer deal with Hertz. Send them the original contract you agreed to, as well as the final bill Hertz is trying to push on you, along the photos of the odometer in case the numbers on the bills don't agree. That's what they are there for.

Wait...when you returned the car, they should have printed a receipt and handed it to you. Did that receipt show 380 euros and an odometer less than 1250k from where you started?

If this was a middle-of-the-night Hertz Local Edition drop, did you get a receipt emailed shortly after the location opened the following morning?

If it's an airport return (or an HLE return when they're open), I never walk away without a paper receipt. If it's a late-night drop, I call the HLE directly if I don't have a receipt by 10AM or so.

My only issue with a credit card charge reversal is that it can get you banned from Dollar and Thrifty as well as Hertz. Maybe if you rent mainly in Europe where Sixt is ubiquitous that's no big deal, but while I don't really like Dollar and Thrifty I still find myself needing them every once in a while. I'd probably try again to get it solved with Hertz.

Agree with what pinniped said as far as advice for future rentals, but for this case:

Since the rental took place in the EU you can try the European Car Rental Conciliation Service (https://www.ecrcs.eu/) after you've exhausted Hertz's dispute resolution process -- it's essentially specialized arbitration. I've never had any issues with Hertz in Europe but every rental I've taken on that side of the pond has included details on the ECRCS

Thanks all for your feedback. I am more upset by the actual process than the cash it cost. I just think it's lousy service. if I were to hassle them, I'd win back approx 100€. I'll save myself the headache, frustration and hassle and just never book with them again.

I'm beginning to think there's more to this story. But go ahead and don't rent from Hertz.