UHG — Illegal construction

Address:

Gurgaon, Haryana, 122002

I live at Sushant Lok phase 1 and the neighbours are contracting illegally and beyond permissible limits. All my backyard has been messed up with cement. When I approached the neighbours they promised to get it all painted and repaired but now they are denying it. Don't know what legal action had to be taken and whom to approach.