Well, too bad we cannot see what you wrote exactly, so this isn't proof for anything. Also, maybe you don't know what good Pizza is? Because the best Pizza even in Italy has parts of the crust burned (actually black!)

It doesn't matter if some people think good pizza should be burnt to some degree. There is no such thing as objectively good pizza, so one-star review "The pizza was burnt, I didn't like it." is entirely valid thing to say.

The entire concept of a review is that it's one person's opinion.

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.