What is the procedure to cancel the flat for which agreement is already done,possession on Dec 2019

Hello All, I have booked one flat ,paid registration and Stamp duty, Loan also sanctioned and 75% of the payment disbursed to the builder. The house design for the booked flat is totally mess. there is no enough space available for Hall, as maximum space combines with Kitchen . The sample flat which they showed us was quite different, though the carpet area is more but the design was good. Based on this designed I booked the flat in 1st floor. but the design didnot impress me and I feel I was cheated because I paid hefty amount to that carpet area (623 sqft)but 50% has been built and the changes which we suggested NOT done, they say it cannot be done. House looks too small (doesnot look like 623 sqft) and the design or the architecture of the house is not good at all unlike the flats on the other side. Now, I am really disappointed and want to cancel that flat and will look for other flat by other builders. Please suggest me : 1. The procedure to cancel the flat for which agreement has already been done. 2. Is it safe to cancel without any severe loss? 3. how to convince the builders ? can we transfer Loan to other builder if we find better flat?? 4. or Please suggest any other alternatives. Contact me [deleted]