Dealing with unfair Google reviews is frustrating, but you aren't powerless....

https://wiki-book.win/index.php/How_to_Handle_a_One-Star_Review_After_Firing_an_Employee:_A_Strategic_Guide

Dealing with unfair Google reviews is frustrating, but you aren't powerless. Some reviews can be removed if they clearly violate Google’s content policies, like spam or conflicts of interest. Keep in mind that outcomes vary and success isn't guaranteed