Here are the steps to complain against a Navi loan: Contact Navi Customer Service:083898-60401, Reach out to Navi's customer service team either by phone, email, or through their website's customer support portal. …Here are the steps to complain against a Navi loan: Contact Navi Customer Service:083898-60401, Reach out to Navi's customer service team either by phone, email, or through their website's customer support portal. …