Rentalcars.com Rentalcars Bait & switch + paid more on arrival Internet

I was doing a standard online search in Kayak, and these guys came up as the cheapest option, so I booked them. I then received a call a couple hours later that said the type of car I wanted to reserve was not available at that price, would I like to pay $30 more for the same car from a different vendor. I wasn't happy about it, but because  the reservation was still pretty cheap and covered liability insurance, unlimited KM and (it said) all local taxes, I thought it was fine. However, I then arrived in France only to find a fairly confused car rental representative when I showed her a paper copy of the reservation I'd made through this agency. Even though the reservation clearly indicated local taxes were included, I was required to pay about 50 euro extra before I could get a car (including airport fee and the VAT which is a tax if I ever of one). I was in absolutely no position to get to the bottom of it then, not speaking French. When I contacted Rentalcars about this, they said that local taxes *were* paid for, and that I was paying additional mandatory fees, which they claim to have clearly outlined on their website. to their credit, the itemized list is there --- but it's right under what is covered (i.e., local taxes). They are currently refusing to do anything to address this. 

I would not recommend this company to my friends, and will not be using them again.