Consumer Redressal

I booked a flat in M3M Woodshire sector 107, Gurgaon and paid 30% amount. It was claimed that location is dwarka expressway but it is 3 Km away from Dwarka expressway. I have not signed any agreement/ allotment letter till date. Now developer has raised more demand. I want to cancel the booking and take refund but developer customer care is asking for deduction of 15% of total consideration and fee paid to broker. So there is going to be loss of Rs. 25 Lakhs. Generally builders deduct 10% on amount paid and that should be Rs. 3-5 lakhs. They also kept my money for 1.5 years. Their customer care department is pathetic and contacting them is just wastage of time. Their agreement is one sided i.e, no penalty for any of their fault but customer has to pay huge penalty for the same. What remedies I have against the builder.