Received a letter from Hertz Germany informing they had charged me 20€ + vat for informing "the relevant authority".

I didnt find this info on any of my receipts, and specifically asked what extras that might occur. This was not mentioned. I e-mailed then about it, and got a standard "reply within 14 days" e-mail. After 15 days I sent a follow-up (which only gave me the same standard reply) saying that no reply within coming Monday would make me assume they didnt backup the charge, and wouldnt mind me disputing the charge with Amex. Called Amex, explained, and they promised money back on card within 48 hours.^

Hertz: a big