Update: Hertz's FT rep offered to look into this and it appears to be a web display error during reservation.
Originally Posted by
TerryK
How did you cancel a prepaid reservation?

Aren't prepaid reservations non-refundable?
I suspect you just saw a pre-authorization.
No. In fact the original charge on my Amex didn't identify the origin other than Hertz. I didn't connect it to this reservation and had Amex put in a chargeback dispute. It's then that Hertz came back and said it was for a prepaid voucher. Amex sent a letter reversing the disputed amours and re-charged my card
So I showed Amex my original confirmation and they went ahead and reversed it a second time. I also contacted hertz who had no problems cancelling it by phone.
It just is not right for Hertz to convert reservations to prepaid without wen an email confirmation or prepaid voucher being issued.