till date flat is not yet complite

Location/place: Bangalore

Name of company/service: M M Residency

We bought flat in M M Residency I wing Miraroad (East) from M M Residency and they show us the sample flat and commit us that they will provide the same flat with all the accessories.
We got Possessionin the month of March 2009 but till date flat is not yet complite we saty in the flat but like beggar. Flat condition is like Footpath staying person.

Please guide us what action we have to taken.