Delivery of flats

Q: Can anyone say if a customer is cheated and is not handed over his flat in proposed time, delivery of the finished flat is unusually delayed what can a customer do against the mighty builders? The builders mention ‘force majeur’ as the reason of delay as a lame excuse to avoid legal consequences and are thus exempted from paying compensation to the customers. But how far is it justified when the delivery is likely to be delayed by more than three long years? Shelter is verbally mentioning labour unrest as ‘force majeur’. But to the question that how can other builders complete their projects in time, they keep mum.