Something like this happened to me too, for what it's worth. I wrote a completely factual description of my bad experience with a shop, and then got a nasty notice from Google that my review was being taken down because of a defamation claim.

I looked up how this works, and I found ads for law firms that specialize in removing bad reviews. They charge a set price for each review they remove. As a regular consumer, you just have to accept that your honest reviews will be removed, unless you're willing to risk going to court, where you'll have to prove that your subjective experience was accurate.