Consumer Redressal

Dear Team, 2 years back I bought a residential flat in MM residency. The property is developed by MM Developers. As per our contractual terms and condition the developer was supposed to handover the peaceful possession of property by 31st December 2013, but till now the construction is not yet completed and developer stop constructing the building after 10th slab from past 8 months. As per the plan the developer is supposed to construct total 16th slab. This contract is violated by the developer and when I trying to call developer at their office no one is responding and sometime people over there is using abuse and offensive language. I took a personal and home loan just to buy this property and put all my savings to buy this property. Now as per the contract developer has to pay an interest from 1st January 2013 but they are not responding. Please help me I am fed-up and mentally harassed