GST ON POST SUPPLY DISCOUNT - Goods and Services Tax - GST

one of my automobile dealer has received commercial credit note in form of performance incentive/ target incentive.Now A.O. is charging output Gst on commercial credit note treating it post supply discount without any agreement with company. In reply, I offered him latest judgement of Hon. madras high court in case of M/s Supreme Paradise - 2024 (2) TMI 351 - MADRAS HIGH COURT where it is clearly mentioned that Unless discount is offered on acocunt of subsidy, it can not form of Transaction value. I also quoted circular No 92/11/2019 where it is clarified that no tax on commercial credit note will be charged. But A.O. denied the submission and charged tax. Pls guide.