Sobha Developers - Sobha Moonstone

I have booked an apt in Sobha Moonstone almost 2 years back by paying an advance of 2 lakhs. After a year long of delays they have got necessary approvals. Feb 08 they made us pay 25% down payment. From then they have hardly constructed as there is a rock and they are unable to blast it. If I move out according to agreement papers I need to lose 5% of the total cost of the project. What are the options do I have? The project will get delayed by at least 2 years, so is it wise moving out? I am afraid if I move to other projects the story might continue.