Test Achats

If you're from the U.K. then you'll probably be familiar with "Which?" magazine. It's the same thing. i.e. they publish a magazine with reviews of products and recommendations for best buys etc. They also have a consumer advocacy / legal department that will answer questions, and give legal advice to members on consumer related issues. (housing / travel / shopping / money / general consumer issues etc.)
I've been here 20 years and have never joined, but I know people who have been members and have used their services to good effect.