Oyo Rooms — Oyo rooms is not reponding even after complaining.

I booked a room in hotel orient flagship on 6th april through oyo app. I paid booking amount through app but when I reached hotel, they told me that booking is invalid and if I want to checkin I will have to pay extra tariff charges which is not mentioned anywhere in the oyo. As I had no other option, I had to pay extra charges i.e. 600₹ apart from 400₹ which I paid while booking, so total bill was summed up to 1000. They also refused to give me bill. Even though I am sharing screenshot of payment done by me. This is totally not expected from oyo. I just want refund for extra money that I paid which is 600₹ as soon as possible. I have contacted oyo service multiple times but it is not worth contacting. Executives are only putting calls on hold for long hours and not responding. Resolve my issue as soon as possible.