Booking Amount not being refunded

Hi, I had booked a flat by paying 25k as per the policy of the builder. I was told at the time of booking that only 10% of total cost of the property I will have to pay for sale agreement and I was not informed anything that I will not get any refund if I cancel the booking. After one month I got a demand notice of 20% of total cost of the flat when I called them that I was told for only 10% then they told me they will take 10% from bank for which I will have to pay pre-EMI which I was not interested in, so I decided to cancel my booking and I called the person who had done the booking and he told me to call the office of the builder. When I called they told me to send a mail regarding cancellation and I did the same. I waited for more than 2 months for my booking amount to get back and then I called their office again and enquired why I did not get reply from the builder regarding my cancellation and the person told me there is no need to reply and the builder has cancelled my booking. Regarding my booking amount, she told me that I will not get because it was written in the application receipt that booking amount is nonrefundable. I asked that then why don't u give me same reason through mail, then she told me she cannot do this. As it had been almost 6 months from the booking and as I was told at the time of booking that within 6 months work will be started on the construction site so I decided to visit the construction site and I found that nothing is being done except for booking of new flats and the new booking amount was 11k and I also got to know from their staff that booking amount also was 5k only for a limited period. Now when I called their office that why their is difference in booking amount and why for the same property someone will give only 5k, 11k and 25k for cancellation of the property. They told me they cannot answer and I will have to meet the manager if I want. When I went their, manager did not have time to meet me and I was told send a mail again and they will reply. Now, I have sent them the mail and mentioned in the mail that I will wait for 15 days and then go through legal ways. So I want to know is there any way that I can get my money back. I know 25k is not a huge money but I don't want my hard earned money to go just for a booking. It is better I will use the same money for some gud work and help someone who is in need. Plz reply