Unfair demand of interest by builder

5 years ago

I am from GGN.

28- May-2018 - I received demand letter from builder for payment of whole amount and gave me a time for 15 days for the payments i.e. 12 june 2018.
30-May-2018 - All documents submitted to builder for loan purpose.
12 June 2018 - Loan sanctioned by bank and intimated to builder.
18 June 2018 - BBA agreement executed by builder and handed over to me on 22nd June 2018.
22 June 2018 - Request submitted to builder for tripartite agreement.
25 June 2018 - Tripartite agreement handed over to me by builder.
02 July 2018 - Final Disbursement of loan was done by bank.

Now my builder is demanding for interest @15% + GST for delay of payments by 20 days where i am not a defaulter. After final words with builder he is asking me to pay interest @8.35%. according to him if things have done on time then i have paid this interest to bank and now i should pay this to builder.
Please tell me whether i am liable to pay this interest to builder or not as i don't have any mistake in this. Loan disbursement was not possible without BBA agreement and Tripartite agreement. Builder made intentional delays just to grab some extra money.