Rera ruling on earnest money deduction

Dear Sir, I had booked a flat with a builder and almost 70% of the value was paid. For some personal reasons I did not like the property and wanted to cancel the booking but then was convinced by the builder to shift the booking in their another project, which is with better facilities, although a lot more expensive than the first one. I got convinced but the builder deducted tax amount, already paid for the first property, and the balance amount was shifted to the new property. The new property's tentative possession time is 2022. After a lot of consideration we decided that we should cancel the booking and request the refund. The builder has sent a letter saying - That as per RERA ruling earnest money @ 10% of the value of the flat shall be deducted. - 50% of the remaining amount, after earnest money deduction, shall be refund within 45 days and balance 50% shall be paid in a period of one year (there is no mention of with interest) Seeking your assistance clarification of the rulings and my rights and actions required, in reference. Regards, NK NK