GST on buyback of leased car

My company is having office in Chennai and has car leased policy. We don’t have office in Hyderabad but we work in Hyderabad. I have leased the Car in May 2019 after GST implementation. The car was leased from Tata capital and car was registered in my name since we didn’t have office in Hyderabad. There is lease agreement between my company and me so that company can get tax benefits. Now 48 months of lease is going to be over and I need to buy back car with 15% residual value on exshowroom. Tata capital is charging gst plus cess for this buy back and removal of hyphotication. I believe since the car is registered in my name GST should not be charged since there will not be sale transaction only removal of hyphotication and paying 15% residual charges to Tata capital. But Tata capital is considering this as sale transaction and charging GST where actual ownership is not changed. Could your please provide your expert advice on this GST charges where there is no sale transaction.