Builder delaying completion of residential apartments in Bangalor

Dear Sir/Madam, My name is Babu, I have booked an 2BHK apartment in Bangalore in 2012. Builder hasn't completed the project yet and delaying. Please suggest what can be done on this? Builder buyer agreement was signed on December, 2012. As per builder buyer agreement, flat was to be delivered on or before 30th June, 2014. Page No 10, clause 20: As per builder buyer agreement page no 10, clause no 20, the vendor/developer agrees to construct and handover the flat with all amenities on or before 30th June, 2014. Any further delay by the developer to deliver the schedule apartment along with all amenities, the vendor shall compensate the purchaser at the rate of 8% per annum on the amount till then paid by the purchaser to the vendor/developer. Builder is saying they have been hit badly by some factors which was beyond there control and to an extent may be you can call it act of god. When we say factors beyond our control the troubled times with the eternal non- availililty of river sand/coarse aggregates and lorry strikes which we hope you are aware has badly hit the construction schedule of all projects all around Bangalore,be it government or private projects which has resulted in delays in completion / handing over of 99% of the residential projects with delays ranging from one year to four years in some projects. Please refer to the clause no.19 on page 10 of our Sale Agreement dated Dec/2012 wherein the point of non availibilty of materials/other factors are mentioned. As per builder buyer agreement page no 10, clause no 19: The vendor/developer shall not incur any liability if the completion of the schedule apartment is delayed by reason beyond the control of the vendor/developer including non-availability of building materials, electricity, sewerage or water connection, government sanctions or by reason of war, civil commotion or any act of god or due to any notice or non availability of the occupation certificate. Regards, Babu