If your business is experiencing unwanted/negative content, you should immediately act to get it removed. This is due to the principle of the situation (no one should get away with an unfair review) but also because the longer the reviews are up, the harder they can be to remove, so acting with haste can be advantageous. The longer you wait, the harder it will be to set things straight, simple as that.
Your business deserves to have an online reputation that is honest and fair. If not dealt with and removed, malicious comments can do irreparable damage to your online reputation. Unfair reviews from disgruntled customers or online trolls means less traffic to your site/store and less revenue for your business. Fight for your reputation. Fight for truth. Otherwise, your competitor’s with better reviews will benefit the most and gain all of your market share.