Non agreement of BPTP Park Floor Sec 76

I had booked a unit in Park floors sec 76 in Aug 2008.

In short our points of contention are the following:
1. How can they charge the interest when they only recieved the approval for this project in March 2011.

2. Can they demand the construction linked payment untill they deliver the project as promised ie. on the 60mtr approach road as they are completely taking their customers for a big ride by delivering a project without any proper link to the project site.

3. Can they charge interest for the period when the project was not approved.

4. Can they charge interest from a customer who did not gave the sanction letter from bank and not charge the interest from the customer who gave the sanction letter ( Although none of the customer made the payment because the bank did not release the payment).

5. They are threatening to cancell the booking without refunding the payment of Rs 4.5 lakhs which we had initally made at the time of booking if we do not make the complete