Help for Recovery of booking amount from a builder

Dear Experts, I recently made a booking for a flat (no agreement made while at booking). Generally, in Bangalore, most of the builders dont give you a copy of documents unless a booking is made. Hence, I had to book for the flat paying the booking amount to get the documents. When I took the set of documents to a real-estate advocate. He pointed out several issues in the documentation and advised us against it (3 weeks from the date of booking). One issue was that the builder had "A Khata", but did not have DC conversion certificate. Also, the building had many deviations (in comparison with the approved building plan). One example to cite was, the builder had converted 1bhk flats to 2 bhk, and 2bhk flats to 3bhk flat. Further, the documents showed a rectangular site, while in reality, the site had portions chopped off (compound was built like that) for rain water drain and other intrusions. In addition, there were pent houses. There was no commencement certificate, No BDA NOC and layout approvals as well. I asked the builder, if they have/can get these certificates, and get us OC. The builder frankly told that there is no certificates, and we have to get it after forming association. I enquired if A khata can be obtained without DC. All the advocate and real estate friends told it was not possible. It took me some time 25 days (4 days addition after legal advice) from date of booking to come to a conclusion that it is risky to move further. I called up the builder and canceled the booking. I also sent them an email to cancel my booking (same day). It has been 15 days, the builder is refusing to pay me back and insisting me that he would pay only 60 thousand maximum. He states that he missed few customers during the period who were ready to buy the flat. I understand that the verification took some time and decision to arrive based on confusing paper work took time. I tried to reason out with the builder to no avail. I am left with legal recourse through consumer forum which I would want to keep as a last resort. Kindly advice. Best regards, Anappa