Loan not approved even after submitting required documents What to do

I bought 02 flats through agent in greater noida.at the time of buying flats agent promised that everything they will take care including loan up till we get posession.loan is not done even after submitting required documents for the last 06 months.can we sue them in the court.we ask them to cancel 01 flat and refund whole money or to transfer the amount in to other flat.as per builder if we cancel flat then booking amount paid will be forfeited as mentioned in prospectus.in this case this is not our fault because we submitted all the documents as required by agent.Please advise....