Deduction from Booking Amount

Following is my situation: I paid a booking amount of Rs. 2 lakhs to the builder in full faith that I will go ahead with the purchase of the house in Bangalore. Around 4 weeks after signing the booking form, I was provided with draft of the House buyers agreement. I found this agreement to be very one-sided, protecting mainly the builder's interests and caring little about the buyer's rights. Hence, I asked the builder to modify the clauses that are not acceptable to me, which the builder flatly refused. Following this, I have asked the booking to be cancelled and the booking amount to be refunded to me. The booking policy states that the builder will deduct Rs. 50,000/- on cancellation of booking after 7 days of signing the booking form. My question: is the builder justified in deducting 50,000 from the booking amount? Is it my mistake that I was provided with the buyers agreement after 4 weeks of signing the booking form? Had it been provided to me at the time of booking I would have not booked the house in the first place. Had it been provided to me within the week's time after the booking I would have still cancelled within the 7 days time. The builder is now refusing the return the entire Rs. 2 lakhs till I agree that he can deduct the Rs. 50,000. Is this justified under the law?