Mental harrasment

Hi Sir. I live in chandigarh with my family.in three storey house. The ground floor is someone else my brother sold his share 50%.,l reside in first floor and the second floor i have given on rent to students doing coaching from Helix institute medical. I am the owner of 50% share of the house. The family living in ground floor senior citizen Mr &Mrs aged 70 years alongwith 32 years daughter unmarried having some problem,both these elderly have heart problems.Now the question concerned is that , tbey keep on complaning and sending falze and misleading letters to different departments. Especially chandigarh estTe office tbat we running illegL PG business.further complaints to police, electricoty and water department. The concerned depRtments visited and checked all the documents and verifiednot PG ,food coming from outside, Tme and again he keeps on complaning to different depaetments after every two months. We along with House owners association ,duly signed bymembers given a complaint to concerned police station that this fellow sends false and misleading complaint s to dicferent department's,because he had complained about diffefent houses that they Re also running illegL pg. Now this iz causing mentL harresment and agonyCouple of times we had verbal duel also..he being a senior citizen is taking undue advantage .please advice