Builder has demanded interest on late payment on possession

I have booked a flat on Sept 2009 and according the builder buyer agreement, the builder is supposed to give me possession of the said flat in September 2011. But in June 2015 builder has given the offer of possession of the flat with the interest of Rs. 300000/- as delay payment on my part. I have booked the flat in 2009 and in September 2010 I have paid the entire amount due to the builder. Payment shedule is as 15% of BSP at the time of booking, 80% of BSP within 45 days of booking and rest 5% is at the time of Possession with additional charges and PLCs. As per the Clause of the BBA is reproduce below “That is other the company fails to deliver possession of the said flat within the stiuplated period as mentioned hereinabove, the allottee shall be entitled to compensation for delay @ Rs. 5/- per sq. ft. Per month for the super area of the said flatl which shall be payable to allottee after execution of sale deed. Provided that if the allottee, at any time, commits default in making timely payment of any installment, or commits breach of any conditions mentioned herein, the allottee will not be entitled to any compensation for delay.” Now, the question is for my default of payment Builder has charged interest of Rs. 300000/- and upon interest he also charged Service Tax @14% Can the builder be also charged for the delay in possession of the flats for 45 months. When I asked for the compensation the builder responded that I have commits default therefore I will not be entitled to any compensation for delay.