Interest charged on delayed payment

Hi, I have purchased an under construction property with Lodha in the year 2022 June, i paid the booking amount of 30000, at the time of booking I stated the Lodha person that I dont have the downpayment till June 2023 they agreed on the condition and gave me lot of verbal assurance and upon the same I booked it and proceed further with the booking. In 2022 September the agreement was supposed to happen but due to a bank mistake as they started charging me the pre-emi before the disbursement, the loan got cancelled and we applied for a new loan, (I have an email from the bank about their mistake), so the new got processed and due to which my agreement was registered in Nov 2022, but as per the payment schedule I behind my payment schedule but somehow I managed to make the down payment and also bank disbursed the amount. Now as per the payment schedule, the RCC level 20 is as per the construction but unfortunately the the builder charged me a huge amount in the month of march 2023 and to repay that amount I took days to arrange as I was not prepared with this all I managed to make my downpayment but now the builder is demanding 3 Lakh as a latepayment and interest on late payment, I have no money I bought the property as a single women for parents some how arranged the downpayment of 10 lakh and paid to the builder paying any interest is not possible for me, I have sent may email to Lodha also did a face to face meeting, I feel this is the biggest mistake of my life to buy the property as a middle class person, I am paying 26 K as a pre emi to the bank, i dont know what to do in this situation.