What action can I take if builder not returning the booking amount

I booked a flat at Central Park-3 (Flower Valley) in Sona, Gurgaon through a “channel partner”. I signed Expression of Interest (EOI) in April’2016 and paid (by cheque) the “booking amount”. The builder mentioned at the time of signing EOI that I can cancel this booking anytime and get a full refund in case I need money later. Now I have a marriage in my family, and the builder is reluctant to cancel my booking. Further they are stalling the issue, saying that no one has cancelled the booking; cancelling the booking will have a penalty; and cancellation request will require internal approvals, which will take significant time (~3months) to refund. This is wrong on builder part because: (1) In April’2016, at the time of booking the flat, they verbally mentioned that I can surrender the unit anytime to get the refund (2) The EOI doesnot state any penalty clause on cancellation (3) I am worried that now they will raise the next demand. Much appreciate your advice on this.