Mental torture by neighbouring car parking owner.

Respected sir, I am a peace loving person living in a housing society. I had purchased an open car parking space measuring 90 sqft from builder while purchase of my residential flat in 2004. It is marked yellow paint lines and with my name board depicting parking number and my name and letters reserved parking on a name plate fixed on the boundry wall on the adjacent to my parking. Whenever my parking was vacant my adjacent parking owner used to park his or his relatives car in my space without informing me which used to cause inconvience to me when I needed to park my vehicle. I time and again sent message through our security guard to ask him to inform me but he started taking things lightly and for granted and in dadagiri style. Therefore in order to put an end to this I erected a small folding device made out of steel square pipe of size 3"X1" and of height 3feet, with radium No Parking Letters on it pasted vertically and erected on the centre of my parking space so that no four wheeler can be parked without lowering this device. With a lock and key arrangement. It does not in anyway obstruct or cause inconvience to any other car or person walking etc. Now, this person is trying to harrass me by asking the federation commitee members to ask me to remove this no parking device, for the reason that it was erected without the permission of society federation, so federation should remove it. ( Note: he is indirectly targeting me through others). What should be my response in case of society federation committee members under his influence, ask me to remove the device? And how can I put an end to this once and for all .