Ola - Increased base fare

I booked an Ola Mini Cab on *th April, **** at around *:** AM from Ola Zone, Kempegowda Airport to Malleswaram. The total booking fare was Rs *** to be paid in cash. The cab arrived within *-* mins and there was no waiting or parking, still I was charged Rs *** as Airport parking charge. After the ride started, I got a message in my Ola App that the ride has been upgraded to Prime Sedan without any extra charge and the fare will remain the same as it was at the time of booking. After the ride ended. the total fare had come to Rs ***. I paid the amount and later called to customer service. I spoke to an associate first, he told me that the booked and assigned cab was both Mini so there is no change but in the final receipt I could see it was mentioned as Prime Sedan. He asked me to uninstall the app, install and check again. He was not able to provide a resolution. I then spoke to supervisor Aditya. He said the increase was because of the Airport parking charge which is calculated after a ride is booked. When I checked I was able to see that all charges including Airport parking charge is calculated before booking the cab. Aditya also confirmed there was no deviation observed in number of kilometers/route/toll. I then spoke to supervisor Pooja. I informed her that all charges like toll, airport parking charge, gst, number of kilometers is the same and anything that has changed after the ride started is the base fare (which is due to upgrade in vehicle by Ola). She denied this and was constantly saying that the calculated fare is correct. She also asked me if I had a screenshot of the fare at the time of booking only then they would've processed a refund. I asked her if every time I book a cab through Ola I should take a screenshot of the fare as proofs. She did not provide a resolution. Three different people from customer care including the supervisors gave me three different reasons for the increase in fare and none of them had an answer to how the base fare changed after the ride started. All calls are recorded by Ola.