Neighbours watchmen harassing and giving mental torture

Mines is a resedential place next to a big showroom (we are immediate neighbours and share a common wall)- this showroom owner has a watchmen who is harrasing and gving mental torture- 1- he says/makes their customers to park their cars infront of my main gate,hence blocking my entry exit. 2- the watchmen threatened my mom when she said "bhaiyaa humaare gate pe gaadi mat lagwaya karon....:" he said ""main tumko dekh loonga"" 3- when i called his owner he openly rejected that his watchmen does that.. 4- he says he's respectable brother figure to him, and the watchmen can do no wrong.. 5- manytimes when i confronted customers they said,"the watchmen made us parK @ your main gate" 6-when i TOLD owner he says "madarchod saare customer jhooth bolte hain" 7-mera watchmen hanumanji(his name) can do no wrong he's a saint* above 8-1,2,3 4,5,6,7 points mentioned incidences happened multiple times WHAT CAN I DO??? PLEASE HELP