How to take action against housing co operative society

[ranganathbabu]

i had booked a 30x40 plot in 2007, paying the full amount to karnataka housing board society vijayanagar bangalore.
Till today i have been waiting and waiting.
i have all the records for payments(bills) as proof.
I have roamed to their office like a dog without any use.
can anyone guide me what to do, i am thinking of going legal kindly guide me....