Defamation

a society member is defaming us along with the watchmen and spreading lies like we are throwing water all the time even though we are only watering only 1 small plant. We had small argument with watchmen since they do not open gate on purpose or respond when asked anything and play loud music on gate since we do not tip them .They also keep watch on us since we are in front of gate. Other members are mostly elderly and dependent on watchmen and overly sweet with them .Now these 2 watchmen do not spare any chance to instigate other members behind back against us and spread lies like throwing water(only watering 1 small plant) , making noise(not true) , throwing food (not true) and others. We do not have any proof as such nor do they since nothing has happened .. Upon instigation, the divorced lady below has complained about us to the committee and written a long letter which is a complete lie.She also threatens that her brother is lawyer and will "handle" us . However committee favors watchmen (same for 20 years) and lady below who is also helping out with committee's legal issues . What are my legal rights and options ? Frustated from all sides .Kindly help