1. You stated "I had booked a property in May 2014 in Kolkata and completed the agreement with 20% of the Flat value". What was the flat value?
2. You also stated "The agreement clause says, 10% of the flat value will be forfeited",
3. Now, it is clear that you will get refund of 10% of the flat value i.e. 50% of the advance amount you have paid to the builder,
4. Was there any clause stating within how many days of cancellation of the agreement you will get back the refund of your advance payment after the necessary deduction?
5. However, the builder is required to refund you your balance amount within a reasonable period & 3 months from the date of cancellation can safely be called as a reasonable period for the said purpose which will be over on 28.2.15,
6. Send a legal notice to him to refund you the said 10% of flat value within 28.2.2015 failing which file a complaint case before the local District Consumer Dispute Redressal Forum, alleging deficiency in service and unfair business practice claiming refund of the said amount, interest , damage and cost.