@Serdarkaya
Flagging a review as private can be an automatic operation (made by an automated filter based on keywords), or manual, if your review have been reported, and checked.
The filter is working on keywords, e.g. prices, because they can be interpreted as spam. However, this is possible to fix, as you can see here below.
A review is made private when it violates the Maps User Contributed Content Policy
A negative review is perfectly fine, but cannot be a blackmail for the business, nor a personal rant
If a claim is not fixed, using a lawyer is much better then using a review as a leverage, like “I will update this review if the issues with my 18 claims are resolved”
Making your review visible again is indeed possible, by modifying and republishing it, as you can read here below
Fixing your issue
As you can read in Flag and fix inappropriate content "If a review you wrote has been flagged and removed, you can fix it yourself. Edit your review to follow Google review policies — for example, you might remove a phone number or URL from the review. Your review will be automatically republished.
Google uses automated spam detection measures to remove reviews that are probably spam. Although legitimate reviews are sometimes inappropriately removed, these spam prevention measures help improve people’s experiences on Google by ensuring that the reviews they see are authentic, relevant, and useful."
So please try to edit your reviews to make them public again.
In addition there is a known issues about visibility of reviews, but normally the issue is impacting a few number of reviews, not all of therm. Please drop a note in the thread, for the team to check your account
Please try also to edit some of your reviews and let us know if the reviews become public again