Ola Cabs - Ola cabs charged too much fare

I am a regular user of OLA cabs and never faced any issue but on * June **, I feel I am cheated by Ola Cabs.
On *st June ****, an evening I have booked an Ola ride from Alkapuri area to the airport in Hyderabad (** km), CRN No. **********. Normal fare is between Rs. ***-***/- only. But they have charged Rs.****/- (****/- fare and Rs. **/- for cancellation of the last ride).
When I have booked the cab that time app was taking too much time to search the cab and calculating the fare but confirm ride tab was enabled. Hence after waiting for a few seconds, I have pressed the confirm booking tab and booked the ride but estimated fare not displayed on the mobile screen even after booking. I got driver details and called him to know how far is he and how much time he will take because the app was showing time to reach driver at my point is ** -** minutes. The driver assured me he will reach within * minutes although he has taken around ** minuits to reach my location. I also tried to book another cab and searched this time estimated fare shown on my screen and it was Rs. ***/-. So I thought that the booked ride fare will also be nearby to this amount. The cab came and my journey started when I have reached the Airport the driver told me to pay Rs.****/- for the ride. I really shocked ask the driver how could it be too high, he told me that he is also surprised but he also informed that the estimated fare was also not shown on their mobile during ride booking. I suddenly tried to contact Ola support tried *-* times but nobody responded from Ola side. I was in hurry to catch my flight hence I asked the driver (mobile no. +************) to help me out but he didn't help and asked to call on Ola and pay the amount immediately as he is getting late. I was also not having any option and as an honest person paid the amount Rs.****/-through paytm.
I was continually trying to connect Ola support but didn't get the connection after getting the boarding pass and passed security checked on the airport. I again called on Ola support and now call connected. I Inform this whole incidence to OLA representative he also confirms that fare was not shown during booking but as you have confirmed the ride and completed ride hence he can't do any help for me. So I asked him to lodge my complaint he registered my complaint and provided complain no. *********.
On *nd June I got a call from Ola and Ola representative inform he can't refund amount because there is no policy. Then I told him I will lodge complain against Ola in consumer forum and through another platform because this is a fraud and only Ola company were aware that customer doesn't have information about fare hence they can impose any charge. After a long discussion, he also realised that Ola has charged too much fare from me for this ride but due to no policy available for such incidence they can not refund the amount but as a regular customer he offered me a coupon of Rs.***/- but I denied to accept it. I told him to provide me with your higher manager no. to escalate the issue but he told me this is the final stage and nobody can help me in this matter. He told me he can only forward my feedback to Ola management and no other way available. Finally, he offered me a coupon of Rs.***/- for the next ride.
As I was not having any option then told him okay. But I am not satisfied with Ola company and want my extra charged money back. I am sensing a big fraud is going on in OLA cabs. Please do the needful for me and also for other customers.