Sorry but I don't think you are able to hire a car in France without a credit card. (17 years' experience!!)

It's do-able but you need to leave a €500 surety bond - and tends to need to be organised with the head office and not the rental branch. If you are agaisnt Credit Cards than why don't you get an AMEX card - it's accepted at most hire offices (or at least Hertz and Avis that I know of).

It's not worth the agravation. Do what I did when I was young and get yourself put onto a friend's credit card (you get a card of your own) and then cut it up when you come home.