How to stop rivals from defaming my name on social media

Let me know how to manage business defamation on social media like consumer complaints forum, whatsapp and facebook, where my personal identity and business names are defamed just to save my rival's point in proving genuineness whereas they are not really genuine but making their stand in open public as Messiah. What ways lawfully I can seek help as Police can't take lawful decisions except calling these people which in my case they didn't even call but given me a complaint paper to file a court suite which im not sure how to put an end to these people once for all.