Builder Deducted unlawful/unjustified amount against my Project

I, booked two units in Gaur City Mall project bearing Unit No. 1858 and 1856 having name as “Gaur Suits” in the year 2019 in the name of RAJAT KUCHAL AND ASSOCIATES, proprietorship firm (Rajat Kuchal, prop.) This Project situated at Greater Noida (west), Dist. Gautam Budha Nagar having RERA NO:- UPRERAPRJ6934. As per project payment plan I paid 50% amount for Unit No 1858 in the year 2019 and balance 50% would be payable at the time of possession of the Unit. I also paid 10% advance against the Unit No 1856 in the year 2020. Further, due to Covid 19 my financial position was not allow to pay balance amount to the promoters accordingly I applied for refund against the Unit No 1858 as on 05.10.2020. As per clause 7.5 of Builder Buyer Agreement there is clearly mentioned that “The Allottee shall have the right to cancel/withdraw his allotment in the project: Provided that where the Allottee proposes to cancel/withdraw from the project without any fault of the Promoter, The Promoter herein is entitled to forfeit the booking amount paid for the allotment. The promoter shall return 50%( fifty percent) of the balance amount of money paid by the Allottee within 45 (forty five) days of such cancellation/withdrawal and remaining 50% (fifity percent) of the balance amount on re-allotment of the apartment/plot/unit or at the end of one year from the date of cancellation/withdrawal by the Allottee, whichever is earlier.” Whereas, Promoter not processed refund application against Unit No 1858 as per the clause of Builder Buyer Agreement. Due to delay in refund, I further requested to the promoter and sent a mail regarding it as on 22.08.2021 to transfer the fund into my other Unit No 1856 without any deduction otherwise pay the refund amount immediately. Whereas, Promoter ignored my request and not paid any refund amount to me, moreover transferred the amount against Unit No 1858 with 40% deduction into other Unit No. 1856. Promoter deduct Rs. 8,17,132/- against Unit No. 1858 and transferred only Rs. 12,30,676/- in my other unit no 1856. When I, visited in the promoter corporate office, Company executive told that theses deductions are as per Builder Buyer Agreement. There are two major deductions. First, 10% booking amount of the Unit i.e. Rs. 3,65,680/- and Second, GST @12% of full amount of Unit value i.e 4,38,816/- I applied for refund as on 05.10.2020, according to Builder Buyer Agreement 50% of refund amount (after deduction of booking amount i.e. 10% Rs. 3,65,680/-) should be paid within 45 days of cancellation and balance 50% should be paid within one year of cancellation. Whereas Promoter not paid any amount to me then there is no right of the promoter to deduct 10% booking amount i.e. 3,65,680/-. Second issue related to GST and I have valid facts against GST deduction. I also applied for RERA conciliation but Builder not accepting the request. Kindly suggest me, what are the best way to handle this situation with Builder,